Recordable optical disk, recording device, recording method, and reproduction device

ABSTRACT

The present invention is to realize a proper inner zone layout in an optical disk having at least three layers. A test area is provided in the inner zone (inner circumference side area) in each of recording layers. The test areas of each layer are so disposed as to be prevented from overlapping with each other in the layer direction. Furthermore, the number of management information recording/reproduction areas overlapping with the test area in the layer direction at a position closer to the laser-incident surface than this test area is set equal to or smaller than one in each test area of each recording layer. The management information recording/reproduction areas are each so disposed as to be prevented from overlapping with the test areas in the respective recording layers in the layer direction on the disk substrate side of the test areas.

TECHNICAL FIELD

The present invention relates to a recordable optical disk such as awrite-once disk and a rewritable disk, a recording device capable ofdealing with a recordable optical disk, a recording method, and areproduction device.

BACKGROUND ART

Optical recording media such as the Blu-ray Disc (registered trademark)are known. In the optical recording media, recording and reproduction ofinformation by use of a semiconductor laser are performed.

The recording to an optical disk by use of a semiconductor laser isgreatly affected by variation in the laser power attributed to thetemperature and change over time, various kinds of skews and offsetsattributed to an adjustment error at the time of the manufacturing, anda recording condition gap in the drive control. Therefore, particularlyfor recordable optical disks such as a write-once disk and a rewritabledisk, variation in the laser drive circuit and the optical element issuppressed and precise light-emission waveform control is carried out.

In an actual information recording device, in general, immediatelybefore data recording, the optimum laser power is sought and therecording laser power and strategy are adjusted to optimize therecording condition by using the test write area (optimum power control(OPC) area) disposed in each recording layer.

In the trial writing process (test write) for this recording laser poweradjustment, removal of the above-described perturbations, optimizationof the recording power, and optimization of the laser drive pulse needto be carried out in the state in which the optimum recording conditionis unclear.

In the seeking of the optimum condition, the test write area isirradiated with laser light having excessively-high energy and the laserirradiation is performed with an improper width of the laser drive pulse(laser emission time) depending on the case. Thus, serious damage ispossibly given to the test writing area in the recording layer.

Furthermore, in a so-called multi-layer optical disk, in which pluralrecording layers are formed over a disk substrate,recording/reproduction of a certain recording layer is affected byanother recording layer.

For example, change in the transmittance of a recording layer attributedto recording occurs, which possibly precludes light irradiation of theintended recording layer with a proper amount of light.

Moreover, the transmittance change has a dependency on the recordingpower. Therefore, the transmittance change, i.e. the degree of theinfluence on the other recording layers, cannot be controlled in a placewhere recording is performed with variation in the recording power likethe OPC area.

These facts lead to a problem that the desired OPC control cannot berealized and derivation of the accurate optimization condition isdifficult depending on the recording statuses of the other recordinglayers.

Specifically, in the case of performing trial writing in the OPC area ina certain recording layer and adjusting the laser power, this trialwriting is affected by the test write area that is in another recordinglayer and disposed at the same position in the planar direction (diskradial direction) as that of this OPC area (i.e. such a position as tooverlap with this OPC area in the thickness direction (=layerdirection)).

To address this problem, as the related arts, there have been devised amethod in which the test writing areas in different recording layers aremutually shifted along the radial direction of the recording layer and amethod in which the same radial position is not used for trial writingbetween the trial writing areas in different recording layers, as isseen in Patent Document 1 shown above, for example.

Also in the double-layer standard of the existing Blu-ray Disc, it isprescribed that the test writing areas of the respective recordinglayers, disposed in the lead-in zone on the disk inner circumferenceside, are so disposed as to be shifted from each other along the radialdirection of the recording layer.

PRIOR ART DOCUMENTS Patent Document

-   Patent Document 1: PCT Patent Publication No. WO05/034110 brochure-   Patent Document 2: Japanese Patent Laid-open No. 2004-295940

SUMMARY OF INVENTION

By the way, for the information recording media, increase in therecording capacity thereof is always required. For example, in the caseof the Blu-ray Disc, it is envisaged that further increase in the numberof recording layers will be advanced for a triple-layer structure and aquadruple-layer structure and significant increase in the capacity willbe realized.

In the development of an optical disk including at least three layers,it is difficult to design the OPC areas in the respective recordinglayers and design the areas where various kinds of managementinformation are recorded and reproduced.

One of the reasons therefor is as follows. Because transmittance changeoccurs due to operation of recording to a recording layer as describedabove, OPC operation and recording/reproduction operation are affectedby another layer. Therefore, the areas need to be designed in view ofthis point.

Moreover, due to the dependency of the transmittance change on therecording power, the degree of the influence on the other layers isindefinite and the transmittance change cannot be predicted. This isalso included in the reasons.

Furthermore, in the design of the OPC areas and the managementinformation areas, compatibility with the existing single-layer disk anddouble-layer disk is also taken into consideration. Thus, all thenecessary areas need to be properly arranged in the predeterminedlimited radial range (e.g. in the lead-in area).

There is a need for the present invention to consider theabove-described points and propose an area arrangement suitable for arecordable multi-layer optical disk.

According to an embodiment of the present invention, there is provided arecordable optical disk as a plural-layer disk including: at least threerecording layers configured to be provided over a disk substrate; and anoptically-transparent layer configured to be formed on a laser-incidentsurface side. In this recordable optical disk, a test area for laserpower control is provided in an inner circumference side area closer toan inner circumference than a data zone in which user data is recordedin each of the recording layers, and the test areas in the recordinglayers are so disposed as to be prevented from overlapping with eachother in a layer direction.

Further, a management information recording/reproduction area forrecording and reproduction of management information is provided in theinner circumference side area in each of the recording layers, and themanagement information recording/reproduction areas are so disposedthat, for each of the test areas in the recording layers, the number ofmanagement information recording/reproduction areas overlapping with thetest area in the layer direction at a position closer to alaser-incident surface than the test area is equal to or smaller thanone.

Still further, the management information recording/reproduction areasare each so disposed as to be prevented from overlapping with the testareas in the recording layers in the layer direction on a disk substrateside of the test areas.

According to another embodiment of the present invention, there isprovided a recording device for a recordable optical disk as aplural-layer disk that includes at least three recording layers providedover a disk substrate and an optically-transparent layer formed on alaser-incident surface side. The recording device includes a controllerconfigured to dispose a test area for laser power control about arespective one of the recording layers in an inner circumference sidearea closer to an inner circumference than a data zone in which userdata is recorded in the respective one of the recording layers of therecordable optical disk in such a way that the test areas are preventedfrom overlapping with each other in a layer direction, the controllercarrying out control to perform information recording after laser poweradjustment by use of the disposed test area.

According to still another embodiment of the present invention, there isprovided a recording method for above-described recordable optical disk.The recording method includes the step of disposing a test area forlaser power control about a respective one of the recording layers in aninner circumference side area closer to an inner circumference than adata zone in which user data is recorded in the respective one of therecording layers of the recordable optical disk in such a way that thetest areas are prevented from overlapping with each other in a layerdirection, and performing information recording after laser poweradjustment by use of the disposed test area.

According to further embodiment of the present invention, there isprovided a reproduction device for a recordable optical disk as aplural-layer disk that includes at least three recording layers providedover a disk substrate and an optically-transparent layer formed on alaser-incident surface side. In the recordable disk, a test area forlaser power control is provided in an inner circumference side areacloser to an inner circumference than a data zone in which user data isrecorded in each of the recording layers, and the test areas in therecording layers are so disposed as to be prevented from overlappingwith each other in a layer direction. And, the reproduction deviceincludes a controller configured to recognize a management informationrecording/reproduction area that is so disposed in the innercircumference side area in each of the recording layers that, for eachof the test areas in the recording layers, the number of managementinformation recording/reproduction areas overlapping with the test areain the layer direction at a position closer to a laser-incident surfacethan the test area is equal to or smaller than one, and the managementinformation recording/reproduction area is prevented from overlappingwith the test areas in the recording layers in the layer direction on adisk substrate side of the test areas, the controller reproducingmanagement information from the management informationrecording/reproduction area and controlling reproduction of user databased on management information.

In these embodiments of the present invention, first the test area (OPCarea) is formed in the inner circumference side area in each of at leastthree recording layers. The test areas in the respective recordinglayers are so disposed as to be prevented from overlapping with eachother in the layer direction. This is to prevent the test area in eachrecording layer from being affected by transmittance change due torecording in the test area in another layer and the dependency of thetransmittance change on the laser power.

Furthermore, the number of management information recording/reproductionareas overlapping with the test area in the layer direction at aposition closer to the laser-incident surface than this test area is setequal to or smaller than one, to thereby minimize the influence of thetransmittance change due to recording and reproduction in the managementinformation recording/reproduction area on the OPC operation in the testarea and achieve compatibility with the existing double-layer disk.

The management information recording/reproduction areas are each sodisposed as to be prevented from overlapping with the test areas in therespective recording layers in the layer direction on the disk substrateside of the test areas. Thereby, recording/reproduction in themanagement information recording/reproduction area is prevented frombeing affected by transmittance change of the test area and thedependency of the transmittance change on the laser power.

The embodiments of the present invention offer an advantage that, in arecordable multi-layer optical disk such as a triple-layer disk and aquadruple-layer disk, proper arrangement in the inner circumference sidearea can be realized and proper OPC operation and recording/reproductionof management information are allowed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an explanatory diagram of the area structure of a diskaccording to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a DMA in the disk of the embodiment.

FIG. 3 is an explanatory diagram of the contents of a DDS in the disk ofthe embodiment.

FIG. 4 is an explanatory diagram of the contents of a DFL in the disk ofthe embodiment.

FIG. 5 is an explanatory diagram of defect list management informationin the DFL and a TDFL in the disk of the embodiment.

FIG. 6 is an explanatory diagram of alternation address information inthe DFL and the TDFL in the disk of the embodiment.

FIG. 7 is an explanatory diagram of a TDMA in the disk of theembodiment.

FIG. 8 is an explanatory diagram of a space bitmap in the disk of theembodiment.

FIG. 9 is an explanatory diagram of the TDFL in the disk of theembodiment.

FIG. 10 is an explanatory diagram of a TDDS in the disk of theembodiment.

FIG. 11 is explanatory diagrams of the layer structure of the disk ofthe embodiment.

FIG. 12 is an explanatory diagram of the inner zone configuration of anexisting double-layer BD-R.

FIG. 13 is an explanatory diagram of the inner zone configuration of anovel triple-layer BD-R.

FIG. 14 is an explanatory diagram of the positions of the respectiveareas in the inner zone of the novel triple-layer BD-R.

FIG. 15 is explanatory diagrams of the tolerance of the respectiverecording layers in a novel triple-layer disk.

FIG. 16 is an explanatory diagram of the inner zone configuration of atriple-layer BD-RE of the embodiment.

FIG. 17 is an explanatory diagram of the inner zone configuration of aquadruple-layer BD-R of the embodiment.

FIG. 18 is an explanatory diagram of the positions of the respectiveareas in the inner zone of the quadruple-layer BD-R of the embodiment.

FIG. 19 is an explanatory diagram of OPC pairs in a quadruple-layer diskof the embodiment.

FIG. 20 is explanatory diagrams of OPC arrangement in the pair in thequadruple-layer disk of the embodiment.

FIG. 21 is explanatory diagrams of the tolerance of the respectiverecording layers in the quadruple-layer disk of the embodiment.

FIG. 22 is an explanatory diagram of the inner zone configuration of aquadruple-layer BD-RE of the embodiment.

FIG. 23 is a block diagram of a disk drive device of the embodiment.

FIG. 24 is flowcharts of processing by the disk drive device of theembodiment.

FIG. 25 is a flowchart of OPC processing by the disk drive device of theembodiment.

FIG. 26 is a flowchart of OPC processing by the disk drive device of theembodiment.

MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will be described below in thefollowing order.

[1. Disk Structure] [2. DMA] [3. TDMA] [4. Plural-layer Disk/Inner Zoneof Existing Double-layer Disk] [5. Inner Zone of Triple-layer Disk ofEmbodiment] [6. Inner Zone of Quadruple-layer Disk of Embodiment] [7.Disk Drive Device] [1. Disk Structure]

First, the outline of an optical disk of the embodiment will bedescribed. This optical disk can be implemented as a write-once disk(BD-R) or a rewritable disk (BD-RE) in the category of a high-densityoptical disk system referred to as the so-called Blu-ray Disc.

One example of the physical parameters of the high-density optical diskof the present embodiment will be described.

As the disk size of the optical disk of the present example, thediameter is 120 mm and the disk thickness is 1.2 mm. That is, from thesepoints, this optical disk is the same as a disk of the CD (Compact Disc)system and a disk of the DVD (Digital Versatile Disc) system in terms ofthe external form.

A so-called blue laser is used as the laser for recording/reproduction,and a high NA (e.g. 0.85) is set for the optical system. Furthermore, anarrow track pitch (e.g. 0.32 μm) and high linear density (e.g. therecording linear density is 0.12 μm) are realized. Based on thesefeatures, about 23 to 25 gigabytes (GB) is realized as the user datacapacity in the 12-cm-diameter disk. Furthermore, it is considered thatcapacity of about 30 GB is also permitted by higher-density recording.

In addition, a so-called multi-layer disk having plural recording layershas also been developed. In the multi-layer disk, the user data capacityis multiplied by the number of layers substantially.

FIG. 1 shows the layout (area configuration) of the entire disk.

As the areas on the disk, the inner zone, the data zone, and the outerzone are disposed from the inner circumference side.

In FIG. 1, the disk is shown with a structure including one recordinglayer (single-layer structure). In this case, the inner zone serves asthe lead-in area, and the outer zone serves as the lead-out area.

The disk of the embodiment is a triple-later disk or a quadruple-layerdisk as described later. In this disk, the inner zone of the first layer(layer L0) serves as the lead-in area. Finally, any of the outer zone ofthe first layer (layer L0) and the subsequent zones (the inner zones andthe outer zones of layers L1, L2, and L3) is employed as the lead-outarea depending on user data capacity recorded thereon.

For convenience of description, the inner circumference side areas ofthe respective recording layers, including the lead-in area of the firstlayer (layer L0), will be referred to collectively as the inner zone.Furthermore, the outer circumference side areas of the respectiverecording layers will be referred to collectively as the outer zone.

In terms of the area configuration relating to recording andreproduction, the area on the innermost circumference side, of the innerzone (lead-in area), is used as the reproduction-only area, and the areafrom the middle of the inner zone to the outer zone is used as therecordable area.

In the reproduction-only area, a BCA (Burst Cutting Area) and PIC(pre-recorded information area) are provided. However, in the inner zonestructure of a multi-layer disk having two or more layers, the PIC isprovided only in the first layer (layer L0) and the part of the sameradius as that of the PIC serves as the recordable area in the secondlayer (layer L1) and the subsequent recording layers, as described indetail later.

In the recordable area in the inner zone, OPC, TDMA, INFO (including DMAand so forth), a reserve area RSV, etc., which will be described later,are formed for recording of management/control information and so forth.

In the reproduction-only area and the recordable area, the recordingtrack based on a wobbling groove (serpentine trench) is formed into aspiral shape. The groove is used as the guide of the tracking in tracingby a laser spot, and data recording/reproduction is performed with thisgroove used as the recording track.

The present example is based on the assumption of an optical disk inwhich data is recorded in the groove. However, the embodiment of thepresent invention is not limited to an optical disk of such a grooverecording system but may be applied to an optical disk of a landrecording system, in which data is recorded in the land between thegrooves. Furthermore, it can be applied also to an optical disk of aland-and-groove recording system, in which data is recorded in thegroove and the land.

The groove used as the recording track has a serpentine shapecorresponding to a wobble signal. Therefore, in a disk drive device forthe optical disk, the wobble signal can be reproduced by detecting bothedge positions of the groove from reflected light of the laser spotemitted onto the groove and extracting a fluctuation component of bothedge positions in the disk radial direction while the laser spot ismoved along the recording track.

In this wobble signal, address information (physical address, otherpieces of additional information, etc.) of the recording track at therecording position thereof is modulated. Thus, in the disk drive device,address control and so forth in data recording/reproduction can becarried out by demodulating the address information and so forth fromthis wobble signal.

The inner zone shown in FIG. 1 is the area inside the position of radius24 mm for example.

In the PIC (pre-recorded information area) in the inner zone, diskinformation such as the recording and reproduction power conditions,information on the areas on the disk, information used for copyprotection, etc. are recorded in advance as reproduction-onlyinformation by the wobbling of the groove. These pieces of informationmay be recorded by embossed pits or the like.

The BCA is provided closer to the inner circumference than the PIC. TheBCA is made by recording the unique ID specific to the disk recordingmedium by e.g. a recording system of burning out the recording layer.Specifically, recorded data in a bar-code manner is formed by formingrecording marks aligned in the form of concentric circles.

Furthermore, in the inner zone, a predetermined area format having aTDMA (Temporary Defect Management Area), an OPC (Optimum Power Controlarea: test write area), an INFO (Information area: managementinformation area), a reserve area RSV, a buffer area BUF, and so forthis set.

The OPC is used for e.g. trial writing in setting the datarecording/reproduction condition such as the laser power at the time ofrecording/reproduction. That is, it is the area for adjustment of therecording/reproduction condition.

The INFO includes a DMA (Defect Management Area) and a control dataarea.

In the control data area, e.g. the disk type, the disk size, the diskversion, the layer structure, the channel bit length, BCA information,the transfer rate, data zone position information, the recording linearvelocity, and information on the recording/reproduction laser power arerecorded.

The DMA is provided in the INFO. In general, in the field of the opticaldisk, alternation management information for defect management isrecorded in the DMA. However, in the disk of the present example,management/control information for realizing not only alternationmanagement for a defect place but also data rewriting in this write-oncedisk is recorded in the DMA. In this case in particular, managementinformation of ISA and OSA to be described later is recorded in the DMA.

To allow data rewriting by utilizing alternation processing, thecontents of the DMA also need to be updated responding to the datarewriting. The TDMA is provided for this updating.

The alternation management information is additionally recorded to theTDMA and updated. In the DMA, the last (latest) alternation managementinformation recorded in the TDMA finally is recorded.

The details of the DMA and the TDMA will be described later.

The INFO including the DMA and so forth is the definitive managementinformation area in which the latest management information is finallystored. The INFO (definitive management information area) is disposedseparately from each other by at least the distance equivalent to theallowable defect size in all the recording layers.

On the other hand, the TDMA is the temporary management information areain which management information is additionally stored on an as-neededbasis. The TDMA (temporary management information area) is disposed ineach recording layer almost evenly for example. In some cases, it isdisposed in the plural recording layers except the recording layerclosest to the disk substrate almost evenly as described later for anexample of the quadruple-layer disk.

The area closer to the outer circumference than the inner zone,specifically e.g. the area corresponding to the radius range of 24.0 to58.0 mm, is used as the data zone. The data zone is the area where userdata are actually recorded and reproduced. The starting address ADdtsand ending address ADdte of the data zone are indicated by the data zoneposition information in the above-described control data area.

In the data zone, an ISA (Inner Spare Area) is provided on the innermostcircumference side of the data zone and an OSA (Outer Spare Area) isprovided on the outermost circumference side of the data zone. The ISAand OSA are used as an alternation area for a defect and data rewriting(overwriting).

The ISA is formed from the start position of the data zone with a sizeequivalent to a predetermined number of clusters (one cluster=65536bytes).

The OSA is formed from the end position of the data zone toward theinner circumference with a size equivalent to a predetermined number ofclusters. The sizes of the ISA and OSA are described in theabove-described DMA.

The leg sandwiched between the ISA and OSA in the data zone is used asthe user data area. This user data area is the normalrecording/reproduction area used for recording and reproduction of userdata normally.

The position of the user data area, i.e. a starting address ADus and anending address ADue, are described in the DMA.

The area closer to the outer circumference than the data zone,specifically e.g. the area corresponding to the radius range of 58.0 to58.5 mm, is used as the outer zone (e.g. lead-out zone).Management/control information is recorded also in the outer zone.Specifically, INFO (control data area, DMA, buffer area) is formed in apredetermined format.

In the control data area, various kinds of management/controlinformation are recorded similarly to the control data area in the innerzone for example. The DMA is prepared as the area in which managementinformation of the ISA and OSA is recorded similarly to the DMA in theinner zone.

The present embodiment has features regarding the structure of the innerzone of a triple-layer disk and a quadruple-layer disk. The layout ofthe respective areas in the inner zone will be described later,including an existing double-layer disk.

[2. DMA]

The structure of the DMA recorded in the inner zone and the outer zonewill be described below. FIG. 2 shows the structure of the DMA.

Here, an example in which the size of the DMA is 32 clusters (32×65536bytes) is shown. The cluster is the minimum unit of data recording.

Of course, the DMA size is not limited to 32 clusters. In FIG. 2, 32clusters are given cluster numbers 1 to 32 to thereby indicate the dataposition of each of the contents in the DMA. Furthermore, the size ofeach of the contents is indicated as the number of clusters.

In the DMA, in the leg of four clusters with cluster numbers 1 to 4,detailed information on the disk is recorded as the disk definitionstructure (DDS).

The contents of this DDS will be described later with FIG. 3. The DDShas a size of one cluster and is repeatedly recorded four times in thisfour-cluster leg.

The leg of four clusters with cluster numbers 5 to 8 serves as the firstrecording area for a defect list DFL (DFL#1). The structure of thedefect list DFL will be described later with FIG. 4. The defect list DFLis data having a size of four clusters, and individual pieces ofalternation address information are listed therein.

The leg of four clusters with cluster numbers 9 to 12 serves as thesecond recording area for the defect list DFL (DFL#2).

Furthermore, the recording areas for the third and subsequent defectlists DFL#3 to DFL#6 are prepared by each group of four clusters, sothat the leg of four clusters with cluster numbers 29 to 32 serves asthe seventh recording area for the defect list DFL (DFL#7).

That is, in the DMA composed of 32 clusters, seven recording areas forthe defect lists DFL#1 to DFL#7 are prepared.

In the case of a BD-R (write-once optical disk), processing of closingneeds to be executed to record the contents of this DMA. In this case,all of seven defect lists DFL#1 to DFL#7 written in the DMA include thesame contents. The written contents are equal to the contents of thelatest TDMA.

In a BD-RE (rewritable optical disk), the TDMA is not provided. This isbecause the DMA may be rewritten every time recording is performed.

The contents of the DDS recorded at the beginning of the DMA of FIG. 2are shown in FIG. 3.

As described above, the DDS has a size of one cluster (=65536 bytes).

In FIG. 3, the “byte position” shows byte 0 as the beginning byte of theDDS composed of 65536 bytes. “The number of bytes” indicates the numberof bytes of each of the data contents.

In two bytes at byte positions 0 and 1, a DDS identifier=“DS” forrecognition that this cluster is a cluster of the DDS is recorded.

In one byte at byte position 2, the DDS format number (version of theformat) is indicated.

In four bytes at byte positions 4 to 7, the number of times of updatingof the DDS is recorded. In the present example, the DMA itself is notupdated, but alternation management information is written thereto atthe time of closing. The alternation management information is updatedin the TDMA. Therefore, when the closing is finally carried out, thenumber of times of updating of the DDS (TDDS: temporary DDS) in the TDMAis recorded at these byte positions.

In four bytes at byte positions 16 to 19, the starting physical sectoraddress of the drive area in the DMA (AD DRV) is recorded.

In four bytes at byte positions 24 to 27, the starting physical sectoraddress of the defect list DFL in the DMA (AD DFL) is recorded.

Four bytes at byte positions 32 to 35 indicate the beginning position ofthe user data area in the data zone, i.e. the position at which the LSN(logical sector number: logical sector address) is “0,” by the PSN(physical sector number: physical sector address).

Four bytes at byte positions 36 to 39 indicate the end position of theuser data area in the data zone by the LSN (logical sector address).

In four bytes at byte positions 40 to 43, the size of the ISA (ISA of asingle-layer disk or ISA in layer 0 of a double-layer disk) in the datazone is indicated.

In four bytes at byte positions 44 to 47, the size of the OSA in thedata zone is indicated.

In four bytes at byte positions 48 to 51, the size of the ISA (ISA inlayer 1 of a double-layer disk) in the data zone is indicated.

In one byte at byte position 52, an alternation area availability flagindicating whether or not data can be rewritten by using the ISA or OSAis indicated. When the whole of the ISA or the OSA has been used, thealternation area availability flag indicates that.

The byte positions other than the above-described positions are regardedas reserves (undefined), and 00h is set at all of these byte positions.

As just described, the DDS includes the addresses of the user data area,the sizes of the ISA and the OSA, and the alternation area availabilityflag. That is, the DDS is used as management/control information forarea management of the ISA and the OSA in the data zone.

Next, the structure of the defect list DFL is shown in FIG. 4.

As described with FIG. 2, the defect list DFL is recorded in therecording area of four clusters.

In FIG. 4, the data position of each of the data contents in the defectlist DFL composed of four clusters is shown as the “byte position.” Therelationship of one cluster=32 sectors=65536 bytes holds, and onesector=2048 bytes.

“The number of bytes” indicates the number of bytes as the size of eachof the data contents.

The beginning 64 bytes in the defect list DFL are used as defect listmanagement information.

In this defect list management information, information for recognitionthat these clusters are clusters of the defect list, the version, thenumber of times of updating of the defect list, the number of entries inthe defect list, etc. are recorded.

At byte position 64 and the subsequent byte positions, pieces ofalternation address information ati each composed of eight bytes arerecorded as the contents of the entries in the defect list.

Immediately after the last effective alternation address informationati#N, terminator information that is composed of eight bytes and servesas the alternation address information termination is recorded.

In this DFL, 00h is set in all the bytes from the byte subsequent to thealternation address information termination to the last of the clusters.

The defect list management information composed of 64 bytes is as shownin FIG. 5.

In two bytes from byte position 0, a character string “DL” is recordedas the identifier of the defect list DFL.

One byte at byte position 2 indicates the format number of the defectlist DFL.

Four bytes from byte position 4 indicate the number of times of updatingof the defect list DFL. This number is the value following the number oftimes of updating of a temporary defect list TDFL to be described later.

Four bytes from byte position 12 indicate the number of entries in thedefect list DFL, i.e. the number of pieces of the alternation addressinformation ati.

Four bytes from byte position 24 indicate the size of the free area ineach of alternation areas ISA0, ISA1, OSA0, and OSA1 by the number ofclusters.

The byte positions other than the above-described positions are used asreserves, and 00h is set at all of these byte positions.

FIG. 6 shows the structure of the alternation address information ati.Specifically, the alternation address information ati indicates thecontents of the entry resulting from alternation processing.

The maximum total number of pieces of the alternation addressinformation ati is 32759 in the case of a single-layer disk.

One piece of the alternation address information ati is composed ofeight bytes (64 bits). The respective bits are represented as bits b63to b0.

In bits b63 to b60, status information (status 1) of the entry isrecorded.

In the DFL, the status information is set to “0000,” which indicates anormal alternation processing entry.

The other status information values will be described later indescription of the alternation address information ati in the TDFL inthe TDMA.

In bits b59 to b32, the starting physical sector address PSN of thealternation-subject cluster is indicated. Specifically, the clusterreplaced due to a defect or rewriting is indicated by the physicalsector address PSN of the beginning sector of the cluster.

Bits b31 to b28 are used as a reserve. Alternatively, another piece ofstatus information (status 2) of the entry may be recorded therein.

In bits b27 to b0, the starting physical sector address PSN of thealternative cluster is indicated.

Specifically, if a cluster is replaced due to a defect or rewriting, thecluster as the alternative thereto is indicated by the physical sectoraddress PSN of the beginning sector of the cluster.

The above-described alternation address information ati is regarded asone entry, and the alternation-subject cluster and the alternativecluster relating to one round of alternation processing are indicated.

Such entries are registered in the defect list DFL having the structureof FIG. 4.

In the DMA, alternation management information is recorded with theabove-described data structure. However, as described above, the time torecord these pieces of information in the DMA is when closing of thedisk is carried out. At this time, the latest alternation managementinformation in the TDMA is reflected.

Alternation processing for defect management and data rewriting andupdating of the alternation management information in response to thealternation processing are carried out in the TDMA to be described next.

[3. TDMA]

The TDMA provided in the inner zone will be described below. The TDMA(temporary DMA) is used as the area in which alternation managementinformation is recorded as with the DMA. However, the TDMA is updatedthrough additional recording of the alternation management informationtherein in response to the occurrence of alternation processing for datarewriting or detection of a defect.

FIG. 7 shows the structure of the TDMA.

The size of the TDMA is e.g. 2048 clusters.

As shown in the diagram, in the first cluster given cluster number 1, aspace bitmap for layer 0 is recorded.

The space bitmap is made by allocating one bit to each of the clustersof the data zone serving as the main data area and the inner zone andthe outer zone, which are the areas in which management/controlinformation is recorded. The space bitmap is used aswriting-presence/absence presenting information that is so configured asto indicate whether or not writing has been completed in the respectiveclusters by the one-bit values.

Although one bit is allocated to each of all the clusters from the innerzone to the outer zone in the space bitmap, this space bitmap can beconfigured with a size of one cluster.

The cluster of cluster number 1 is used as the space bitmap for layer L0(first layer). The cluster of cluster number 2 is used as the spacebitmap for layer L1 (second layer). Although not shown in the diagram,in the case of a triple-layer disk and a quadruple-layer disk, the spacebitmaps for layer L2 (third layer) and layer L3 (fourth layer) areprepared in clusters of predetermined cluster numbers. For example,cluster numbers 3 and 4 are allocated to these space bitmaps.

In the TDMA, a TDFL (Temporary Defect List) is additionally recorded inthe beginning cluster of the unrecorded area in the TDMA if alternationprocessing is executed because of change of data content or the like.Therefore, in the case of a double-layer disk, the first TDFL isrecorded at the position of cluster number 3 as shown in the diagram. Inthe case of a single-layer disk, the first TDFL is recorded at theposition of cluster number 2 because the space bitmap for layer L1 isunnecessary. From then on, in response to the occurrence of alternationprocessing, the TDFL is additionally recorded at the cluster positionswith the intermediary of no unrecorded area between the recordedclusters.

The size of the TDFL is in the range of one cluster to four clusters.

Because the space bitmap is information indicating the writing status ofeach cluster, it is updated responding to the occurrence of datawriting. In this case, the new space bitmap is recorded from thebeginning of the free area in the TDMA similarly to the TDFL.

That is, in the TDMA, the space bitmap or the TDFL is additionallyrecorded on an as-needed basis.

As described next about the configurations of the space bitmap and theTDFL, a TDDS (temporary DDS (temporary disc definition structure)) asdetailed information of the optical disk is recorded in the rearmostsector (2048 bytes) of one cluster used as the space bitmap and therearmost sector (2048 bytes) of one to four clusters used as the TDFL.

FIG. 8 shows the configuration of the space bitmap.

As described above, the space bitmap is a bitmap that represents therecorded/unrecorded state of one cluster on the disk by one bit, and inwhich e.g. “1” is set to the corresponding bit if the cluster is in theunrecorded state. FIG. 8 shows a space bitmap for the case of adouble-layer disk as an example of the bitmap that holds informationindependent on a layer-by-layer basis. In the case of a triple-layerdisk and a quadruple-layer disk, this bitmap is expansively treated.

In FIG. 8, 32 sectors in one cluster are shown as sectors 0 to 31. The“byte position” is shown as the byte position in the sector.

In the beginning sector 0, management information of the space bitmap isrecorded.

In two bytes from byte position 0 of sector 0, “UB” is recorded as thespace bitmap ID (Un-allocated Space Bitmap Identifier).

In one byte at byte position 2, the format version (format number) isrecorded and e.g. “00h” is set therein.

In four bytes from byte position 4, the layer number is recorded.Specifically, whether this space bitmap corresponds to layer L0 or layerL1 is indicated.

In 48 bytes from byte position 16, bitmap information (BitmapInformation) is recorded.

The bitmap information is composed of pieces of zone informationcorresponding to a respective one of the inner zone, the data zone, andthe outer zone (Zone Information for Inner Zone) (Zone Information forData Zone) (Zone Information for Outer Zone).

Each of the pieces of zone information is composed of 16 bytes.Specifically, in each of the pieces of zone information, four bytes areallocated to each of the start position of the zone (Start Cluster FirstPSN), the start position of the bitmap data (Start Byte Position ofBitmap data), the size of the bitmap data (Validate Bit Length in Bitmapdata), and a reserve.

In the start position of the zone (Start Cluster First PSN), the startposition of the zone on the disk, i.e. the start address in turning thezone into the bitmap, is indicated by the PSN (physical sector address).

In the start position of the bitmap data (Start Byte Position of Bitmapdata), the start position of the bitmap data relating to the zone isindicated by the number of bytes as the relative position from theUn-allocated Space Bitmap Identifier at the beginning of the spacebitmap.

In the size of the bitmap data (Validate Bit Length in Bitmap data), thesize of the bitmap data of the zone is indicated by the number of bits.

From byte position 0 of the second sector (=sector 1) of the spacebitmap, actual bitmap data (Bitmap data) are recorded. The size of thebitmap data is one sector per 1 GB.

The area from the byte subsequent to the last bitmap data to the byteprevious to the final sector (sector 31) is used as reserves and “00h”is set therein.

In the final sector (sector 31) of the space bitmap, the TDDS isrecorded.

Management by the above-described bitmap information is as follows.

First, a description will be made about the case of a space bitmap inwhich layer L0 is indicated as the layer number at byte position 4, i.e.a space bitmap corresponding to layer L0 of a single-layer disk or amulti-layer disk.

In this case, information on the inner zone in layer L0, i.e. thelead-in zone, is indicated by Zone Information for Inner Zone.

By the start position of the zone (Start Cluster First PSN), the PSN ofthe start position of the inner zone (in this case, the lead-in zone) isindicated as shown by a full-line arrowhead.

By the start position of the bitmap data (Start Byte Position of Bitmapdata), the position of the bitmap data corresponding to the inner zonein this space bitmap (information indicating byte position 0 in sector1) is indicated as shown by a dashed line.

By the size of the bitmap data (Validate Bit Length in Bitmap data), thesize of the bitmap data for the inner zone is indicated.

In Zone Information for Data Zone, information on the data zone in layerL0 is indicated.

By the start position of the zone (Start Cluster First PSN), the PSN ofthe start position of the data zone is indicated as shown by a full-linearrowhead.

By the start position of the bitmap data (Start Byte Position of Bitmapdata), the position of the bitmap data corresponding to the data zone inthis space bitmap (information indicating byte position 0 in sector 2)is indicated as shown by a dashed line.

By the size of the bitmap data (Validate Bit Length in Bitmap data), thesize of the bitmap data for the data zone is indicated.

By Zone Information for Outer Zone, information on the outer zone inlayer L0 (e.g. the lead-out zone of a single-layer disk) is indicated.

By the start position of the zone (Start Cluster First PSN), the PSN ofthe start position of the outer zone is indicated as shown by afull-line arrowhead.

By the start position of the bitmap data (Start Byte Position of Bitmapdata), the position of the bitmap data corresponding to the outer zonein this space bitmap (information indicating byte position 0 in sectorN) is indicated as shown by a dashed line.

By the size of the bitmap data (Validate Bit Length in Bitmap data), thesize of the bitmap data for the outer zone is indicated.

Similar management is carried out also in the space bitmaps about thesecond and subsequent recording layers such as layer L1. For example, inthe space bitmap about layer L1, management of the inner zone, the datazone, and the outer zone about layer L1 is carried out as shown by theone-dot chain lines.

Next, the configuration of the TDFL (temporary DFL) will be described.As described above, the TDFL is recorded in the free area subsequent tothe space bitmap in the TDMA, and is additionally recorded at thebeginning of the free area in response to every updating.

FIG. 9 shows the configuration of the TDFL.

The TDFL is composed of one to four clusters. As is apparent fromcomparison with the DFL of FIG. 4, the contents of the TDFL are the sameas those of the DFL in that the beginning 64 bytes are used as defectlist management information and pieces of alternation addressinformation ati each composed of eight bytes are recorded at byteposition 64 and the subsequent byte positions, and in that eight bytessubsequent to the last alternation address information ati#N are used asthe alternation address information termination.

However, in the TDFL composed of one to four clusters, a temporary DDS(TDDS) is recorded in 2048 bytes as the last sector thereof, differentlyfrom the DFL.

In the case of the TDFL, 00h is set in the area to the byte previous tothe final sector of the cluster to which the alternation addressinformation termination belongs. The TDDS is recorded in the finalsector. If the alternation address information termination belongs tothe final sector of the cluster, 0 is set in the area to the byteprevious to the final sector of the next cluster, and the TDDS isrecorded in the final sector.

The defect list management information composed of 64 bytes is similarto that in the DFL described with FIG. 5.

However, as the number of times of updating of the defect list by fourbytes from byte position 4, the serial number of the defect list isrecorded. Due to this feature, the serial number of defect listmanagement information in the latest TDFL indicates the number of timesof updating of the defect list.

Furthermore, values at the timing of updating of the TDFL are recordedas the number of entries in the defect list DFL, i.e. the number ofpieces of the alternation address information ati, by four bytes frombyte position 12 and the size (the number of clusters) of the free areain each of the alternation areas ISA0, ISA1, OSA0, and OSA1 by fourbytes from byte position 24.

The structure of the alternation address information ati in the TDFL isalso similar to that of the alternation address information ati in theDFL shown in FIG. 6. The alternation address information ati is regardedas one entry and the alternation-subject cluster and the alternativecluster relating to one round of alternation processing are indicated.Such entries are registered in the temporary defect list TDFL having thestructure of FIG. 9.

However, as status 1 of the alternation address information ati in theTDFL, “0101” or “1010” is often set besides “0000.”

“0101” or “1010” is set as status 1 when physically-consecutive pluralclusters are collectively subjected to alternation processing andalternation management (burst transfer management) for these pluralclusters is collectively carried out.

Specifically, if status 1 is “0101,” the starting physical sectoraddress of the alternation-subject cluster and the starting physicalsector address of the alternative cluster in the alternation addressinformation ati indicate the alternation-subject and the alternativeabout the beginning cluster of physically-consecutive plural clusters.

If status 1 is “1010,” the starting physical sector address of thealternation-subject cluster and the starting physical sector address ofthe alternative cluster in the alternation address information atiindicate the alternation-subject and the alternative about the lastcluster of physically-consecutive plural clusters.

Therefore, in the case of carrying out alternation management forphysically-consecutive plural clusters collectively, the alternationaddress information ati does not need to be recorded as an entry forevery one of all the plural clusters, but it is enough that two piecesof the alternation address information ati about the beginning clusterand the end cluster are recorded as entries.

As described above, the TDFL basically has the same structure as that ofthe DFL but has characteristics that the size thereof can be extended tofour clusters, the TDDS is recorded in the last sector, burst transfermanagement is permitted as the alternation address information ati, andso forth.

In the TDMA, the space bitmap and the TDFL are recorded as shown in FIG.7. As described above, the temporary disk definition structure (TDDS) isrecorded in 2048 bytes as the last sector of the space bitmap and theTDFL.

The structure of this TDDS is shown in FIG. 10.

The TDDS is composed of one sector (2048 bytes) and includes the samecontents as those of the DDS in the above-described DMA. Although thesize of the DDS is one cluster (65536 bytes), the area where substantialcontents are defined in the DDS is the area to byte position 52 asdescribed with FIG. 3. That is, the substantial contents are recorded inthe beginning sector of one cluster. Therefore, the TDDS can encompassthe contents of the DDS although the size thereof is one sector.

As is apparent from comparison between FIG. 10 and FIG. 3, the TDDS hascontents similar to those of the DDS at byte positions 0 to 53. However,in the TDDS, the TDDS serial number is recorded from byte position 4.The starting physical address of the drive area in the TDMA is recordedfrom byte position 16. The starting physical address of the TDFL in theTDMA (AD DFL) is recorded from byte position 24.

At byte position 1024 and the subsequent byte positions in the TDDS,information that is absent in the DDS is recorded.

In four bytes from byte position 1024, the physical sector address PSNof the outermost circumference of the data-recorded area in the userdata area is recorded.

In four bytes from byte position 1028, the starting physical sectoraddress of the latest space bitmap for layer L0 in the TDMA (AD BP0) isrecorded.

In four bytes from byte position 1032, the starting physical sectoraddress of the latest space bitmap for layer L1 in the TDMA (AD BP1) isrecorded.

In one byte at byte position 1036, a flag to control the use of theoverwriting function is recorded.

The bytes other than those at these byte positions are used as reserves,and all the contents thereof are 00h.

However, for example in the case of a triple-layer disk, predeterminedbyte positions in the reserves are decided, and the starting physicalsector address of the latest space bitmap for layer L2 in the TDMA (ADBP2) is recorded at these positions.

In the case of a quadruple-layer disk, predetermined byte positions inthe reserves are decided, and the starting physical sector address ofthe latest space bitmap for layer L2 in the TDMA (AD BP2) and thestarting physical sector address of the latest space bitmap for layer L3(AD BP3) are recorded.

Furthermore, at any positions regarded as the reserve in FIG. 10, thenext OPC operation executable addresses (Next available Ln OPC Address)about the OPC areas in the respective layers are each recorded by fourbytes. That is, the addresses of the parts to be used next for the OPCoperation are recorded.

For example, in the case of a triple-layer disk, the starting addressesof the unused parts (parts where the OPC operation has not yet beencarried out) in the respective OPC areas provided in layers L0, L1, andL2 as described later are each described by four bytes as the address ofthe part to be used next in general.

In the case of a quadruple-layer disk, the starting addresses of theunused parts in the respective OPC areas provided in layers L0, L1, L2,and L3 as described later are each described by four bytes as theaddress of the part to be used next in general.

However, as described later for an example of FIG. 26, “Next availableLn OPC Address” as the address of the part to be used next is oftenchanged to the address of the position that is not at the beginning ofthe unused part.

As just described, the TDDS includes the address of the user data area,the sizes of the ISA and the OSA, and the alternation area availabilityflag. That is, the TDDS is used as management/control information forarea management of the ISA and the OSA in the data zone. The TDDS is thesame as the DDS in this point.

Moreover, the TDDS has the information indicating the positions of thelatest effective space bitmaps (AD BP0, AD BP1 (in addition, AD BP2, ADBP3)), and has the information indicating the position of the latesteffective temporary DFL (TDFL) (AD DFL).

In addition, the TDDS has the next OPC operation executable addresses(Next available Ln OPC Address) indicating the unused parts of the OPCareas in the respective layers.

This TDDS is recorded in the final sector of the space bitmap and theTDFL. Therefore, a new TDDS is recorded every time the space bitmap orthe TDFL is added. Thus, in the TDMA of FIG. 7, the TDDS in the lastadded space bitmap or TDFL is the latest TDDS, and the latest spacebitmap and the TDFL are indicated therein.

A simple description will be made below about updating of the TDMA.

Alternation processing by use of the ISA and the OSA shown in FIG. 1,which serve as alternation areas, is executed in the following manner.The case of data rewriting is taken as an example. For example, supposethat a request for data writing to a cluster in which data has beenalready recorded in the user data area, i.e. a request for rewriting, isissued. In this case, writing to this cluster is impossible because thedisk is a write-once disk. Therefore, this rewriting data is written toa certain cluster in the ISA or the OSA. This is the alternationprocessing.

This alternation processing is managed as the entry of theabove-described alternation address information ati. Specifically, onepiece of the alternation address information ati is recorded as an entrythat indicates the address of the cluster in which data has beenoriginally recorded as the alternation-subject and indicates the addressof the cluster in which the rewriting data is written in the ISA or theOSA as the alternative.

That is, in the case of data rewriting, rewriting data is recorded inthe ISA or the OSA, and the alternation of the data position due to thisrewriting is managed by the alternation address information ati in theTDFL in the TDMA. Thereby, despite the write-once disk, data rewritingcan be substantially realized (from the viewpoint of e.g. the OS of ahost system and the file system).

Similar operation is carried out also in the case of defect management.If a certain cluster is regarded as a defect area, data that should bewritten therein is written in a certain cluster in the ISA or the OSA byalternation processing. For management of this alternation processing,one piece of the alternation address information ati is recorded as anentry.

Furthermore, in response to recording operation (cluster consumption),updating of the space bitmap is also performed.

In this manner, in the TDMA, the space bitmap and the TDFL are updatedon an as-needed basis in response to data rewriting and alternationprocessing. At the time of closing, the contents of the latest TDMA arerecorded in the DMA in the INFO, so that the management information issettled.

In a multi-layer disk such as a triple-layer disk and a quadruple-layerdisk, the TDMA is disposed in all or part of the respective recordinglayers as described later. These TDMAs are used for updating of theTDFL/space bitmap in such a manner as to be exhausted in turn. Due tothis feature, the TDMAs in the respective recording layers arecollectively used as one large TDMA, and thus the plural TDMAs can beefficiently used.

Furthermore, the effective TDFL/space bitmap can be grasped by merelyseeking the last recorded TDDS irrespective of the TDMAs in therespective layers.

Moreover, although not shown in FIG. 7, for determination of the latestTDMA, a first predetermined number of clusters in the TDMA are used as aTDMA access indicator only in the beginning TDMA (e.g. TDMA#1 to bedescribed later).

Supposing that 12 TDMAs, TDMA0 to TDMA11, are provided in the entiredisk, the first 12 clusters in the beginning TDMA0 are used as the TDMAaccess indicator and each represent information of recording of arespective one of TDMAs 1 to 11 and the DMA.

During the use of the beginning TDMA0, no data is recorded in the TDMAaccess indicator. When the whole of TDMA0 has been used and the use ofTDMA1 is started, e.g. “00h” data is recorded in the whole of the firstcluster (corresponding to TDMA1) of the TDMA access indicator. When thewhole of TDMA1 has been used and the use of TDMA2 is started, e.g. “00h”data is recorded in the whole of the second cluster (corresponding toTDMA2) of the TDMA access indicator. If the TDMA access indicator isused in this manner, the following advantage is achieved. Specifically,e.g. at the time of loading of the disk, the disk drive device can getto know the TDMA in which the TDMA data that is the latest at thistiming is recorded by accessing the first TDMA0 and reading the TDMAaccess indicator. If “00h” has been already recorded in all of 12clusters of the TDMA access indicator, the disk drive device can get toknow that data is recorded in the DMA.

[4. Plural-Layer Disk/Inner Zone of Existing Double-Layer Disk]

The layer structures of multi-layer disks will be described below withFIG. 11.

FIG. 11( a) schematically shows the layer structure of an existingdouble-layer disk, and FIGS. 11( b) and 11(c) schematically show thelayer structure of a triple-layer disk and a quadruple-layer disk of theembodiment, respectively.

Each of the disks of FIGS. 11( a), 11(b), and 11(c) has a disk substrate201 having a thickness of about 1.1 mm. The disk substrate 201 is shapedby e.g. injection molding of a polycarbonate resin. A stamper is set ina mold for the injection molding, and thereby the disk substrate 201 towhich a groove shape is transferred is formed.

In the case of the double-layer disk, as shown in FIG. 11( a), the firstlayer (layer L0) is formed on the substrate 201, and the second layer(layer L1) is formed with the intermediary of an intermediate layer 204.Furthermore, an optically-transparent layer 203 is formed on the secondlayer (layer L1).

The surface of the optically-transparent layer 203 serves as thelaser-incident surface.

The optically-transparent layer 203 is formed for the purpose ofprotecting the optical disk. Recording and reproduction of aninformation signal are performed by e.g. focusing of laser light onlayer L0 or L1 through the optically-transparent layer 203.

The optically-transparent layer 203 is formed by e.g. spin-coating of aUV-curable resin and curing thereof by UV irradiation. Alternatively, itis also possible to form the optically-transparent layer 203 by using aUV-curable resin and a polycarbonate sheet or an adhesive layer and apolycarbonate sheet.

The optically-transparent layer 203 has a thickness of about 100 μm.When it is combined with the substrate 201 having a thickness of about1.1 mm, the thickness of the entire optical disk is about 1.2 mm.

The triple-layer disk of FIG. 11( b) includes three recording layers,i.e. layers L0, L1, and L2.

Also in this disk, layers L0, L1, and L2 are formed over the substrate201 with the intermediary of the intermediate layers 204.

The quadruple-layer disk of FIG. 11( c) includes four recording layers,i.e. layers L0, L1, L2, and L3. Also in this disk, layers L0, L1, L2,and L3 are formed over the substrate 201 with the intermediary of theintermediate layers 204.

Each of the intermediate layers 204 in FIGS. 11( a), (b), and (c) isformed by e.g. rotational coating of an optically-transparent materialhaving UV-photosensitivity by a spin-coating method and curing thereofby UV irradiation.

In the case of performing recording/reproduction of an informationsignal to/from a multi-layer optical disk recording medium, thearrangement and film thickness of this intermediate layer 204 aredesigned for the purpose of suppressing inter-layer crosstalk.

In the triple-layer disk, layer L2 is provided at a position distantfrom the laser-incident surface by about 50 μm. In the quadruple-layerdisk, the thickness of the intermediate layers 204 is adjusted and layerL3 is provided at a position distant from the laser-incident surface byabout 50 μm.

The triple-layer disk of FIG. 11( b) is manufactured through thefollowing procedure (ST1 to ST7) for example.

(ST1) The disk substrate 201 to which the groove pattern of layer L0 istransferred is fabricated by injection molding with use of a stamper forlayer L0.(ST2) A recording film is deposited on the groove pattern for L0 bysputtering or the like to form layer L0.(ST3) A resin is extended on layer L0 by spin-coating and the resin iscured while a stamper for layer L1 is pressed against the resin.Thereby, the intermediate layer 204 to which the groove pattern of layerL1 is transferred is formed.(ST4) A recording film is deposited on the groove pattern for L1 bysputtering or the like to form layer L1.(ST5) A resin is extended on layer L1 by spin-coating and the resin iscured while a stamper for layer L2 is pressed against the resin.Thereby, the intermediate layer 204 to which the groove pattern of layerL2 is transferred is formed.(ST6) A recording film is deposited on the groove pattern for L2 bysputtering or the like to form layer L2.(ST7) The optically-transparent layer 203 is formed by a technique suchas spin-coating and curing, or sheet bonding.

Through the above-described steps, the triple-layer disk ismanufactured.

In the case of the quadruple-layer disk, the steps for layer L3 areadded, so that it is manufactured through the following procedure (ST11to ST19) for example.

(ST11) The disk substrate 201 to which the groove pattern of layer L0 istransferred is fabricated by injection molding with use of a stamper forlayer L0.(ST12) A recording film is deposited on the groove pattern for L0 bysputtering or the like to form layer L0.(ST13) A resin is extended on layer L0 by spin-coating and the resin iscured while a stamper for layer L1 is pressed against the resin.Thereby, the intermediate layer 204 to which the groove pattern of layerL1 is transferred is formed.(ST14) A recording film is deposited on the groove pattern for L1 bysputtering or the like to form layer L1.(ST15) A resin is extended on layer L1 by spin-coating and the resin iscured while a stamper for layer L2 is pressed against the resin.Thereby, the intermediate layer 204 to which the groove pattern of layerL2 is transferred is formed.(ST16) A recording film is deposited on the groove pattern for L2 bysputtering or the like to form layer L2.(ST17) A resin is extended on layer L2 by spin-coating and the resin iscured while a stamper for layer L3 is pressed against the resin.Thereby, the intermediate layer 204 to which the groove pattern of layerL3 is transferred is formed.(ST18) A recording film is deposited on the groove pattern for L3 bysputtering or the like to form layer L2.(ST19) The optically-transparent layer 203 is formed by a technique suchas spin-coating and curing, or sheet bonding.

Through the above-described steps, the quadruple-layer disk ismanufactured.

For comparison with the triple-layer disk and the quadruple-layer diskof the embodiment to be described later, the layout of the inner zone ofan existing double-layer disk will be described below with FIG. 12.

The inner zone is set in the radial position range of 21.0 mm to 24.0mm.

The BCA is formed from a radial position of 21.0 mm.

In each of layers L0 and L1, a protection zone PZ1 is provided from aradial position of 22.2 mm for the purpose of separating the BCA fromthe area where recording/reproduction of management information isperformed.

In layer L0, the PIC, in which reproduction-only management informationis recorded by the wobbling groove as described above, is formed in theradial position range of 22.5 mm to about 23.1 mm.

In layer L0, the area to this PIC serves as the reproduction-only area.

In the area from the PIC toward the outer circumference to a radialposition of 24.0 mm, a protection zone PZ2, a buffer area BUF, INFO#2,OPC(L0), TDMA#1, and INFO#1 are sequentially disposed.

In layer L1, in the radial position range of 22.5 mm to about 24.0 mm,the buffer area BUF, OPC(L1), the reserve area RSV, INFO#4, TDMA#2, thereserve area RSV, and INFO#3 are sequentially disposed.

The buffer area BUF is an area that is not used forrecording/reproduction of management information. The reserve area RSVis an area that is not used currently but will be possibly used forrecording/reproduction of management information in the future.

The OPC area as the test write area is provided in each layer. In thedescription of the areas in the inner zone, representation “OPC(Lx)”refers to “the OPC area existing in layer Lx.”

Although the TDMA and the INFO are shown with symbols #1 to #n, they arecollectively used as one TDMA area and one INFO area as a wholeirrespective of the layers in which they are disposed.

[5. Inner Zone of Triple-Layer Disk of Embodiment]

The inner zone of the triple-layer disk of the embodiment will bedescribed below.

This triple-layer disk realizes capacity of about 33 GB per one layerdue to increase in the recording density. An inner zone layout properfor this case is necessary.

First, points P1 to P6 to which attention is paid in the development ofthe triple-layer disk will be described.

(P1) The Anchor Positions are Fixed.

In view of the existing double-layer disk, consideration is given to theusability and compatibility of the inner zone for the disk drive device.For this purpose, the positions indicated by arrowheads F in FIG. 12,i.e. the BCA termination (radial position 22.2 mm), the termination ofthe protection zone PZ1 (radial position 22.5 mm), and the inner zonetermination (radial position 24.0 mm), are fixed.

That is, the PIC, the OPC, the TDMA, and so forth are arranged in theradial position range of 22.5 mm to 24.0 mm. However, slight variationin the radial position occurs due to the difference in the data lineardensity among the double-layer disk, the triple-layer disk, and thequadruple-layer disk.

(P2) The OPC areas in the respective layers are prevented fromoverlapping with each other in the layer direction.

This point is to properly carry out the OPC operation. When recording toa recording layer is performed, change in the transmittance of therecording layer occurs, and the transmittance change has a dependency onthe recording power. Thus, a variety of transmittance changes occur inthe place where recording is performed with variation in the recordingpower like the OPC area. If a certain OPC area overlaps with another OPCarea in the layer direction, possibly proper OPC operation cannot becarried out in the OPC area remoter from the laser-incident surface(closer to the disk substrate 201).

For example, suppose that OPC(L0) overlaps with OPC(L1). Due to OPCoperation with variation in the laser power in OPC(L1), thetransmittance of OPC(L1) varies on a part-by-part basis. After this,laser irradiation with the intended power for OPC(L0) remoter from thelaser-incident surface is impossible due to the influence of thetransmittance change in OPC(L1). Furthermore, laser irradiation withexcessive power is often performed for the OPC area, and thus therecording layer is often damaged.

For these reasons, overlapping of the OPC areas in the layer directioncauses an obstacle to operation in the OPC area closer to the disksubstrate 201. Thus, the OPC areas in the respective layers need to beprevented from overlapping with each other in the layer direction.

(P3) The management information capacity of the existing double-layerdisk is followed.

The PIC is written fivefold as with the existing single-layer disk anddouble-layer disk, and it is enough that it exists in at least onerecording layer.

For example, as the PIC in the double-layer disk shown in FIG. 12, thesame information is repeatedly recorded five times for safety ofinformation and sureness of readout. This scheme is followed also in thetriple-layer disk. Therefore, the radial range of the PIC depends on theamount of data corresponding to five times of recording.

Furthermore, the following characteristics are also followed: the sizeof the TDMA is 2048 clusters per one layer, and the size of the OPC areain each layer is also 2048 clusters. This is to avoid change in theusability of the TDMA and the OPC.

Thus, in the triple-layer disk, 2048×3=6144 clusters are ensured for theTDMA in total. For the OPC area, 2048 clusters are ensured in eachlayer.

Updating of the TDMA accompanies recording operation. Therefore, e.g. inthe case of a device in which the recording laser power is adjusted inthe OPC area immediately before recording operation, the OPC area issimilarly consumed through frequent TDMA updating accompanying diskeject operation and so forth. Thus, the capacity of the TDMA is disposedas evenly as possible in the respective layers in which the TDMA can bedisposed.

(P4) The management information recording/reproduction area is not sodisposed as to overlap with the OPC area at a position closer to thedisk substrate 201 than this OPC area.

The “management information recording/reproduction area” is the genericterm of the areas where recording/reproduction of management/controlinformation is performed in the inner zone. That is, the INFO, the TDMA,and the reserve area RSV are equivalent to the management informationrecording/reproduction area. Because the reserve area RSV will bepossibly used for recording/reproduction of management information inthe future, it is included in the management informationrecording/reproduction area.

Because the PIC is a reproduction area, it is not included in themanagement information recording/reproduction area. Furthermore, thebuffer area BUF and the protection zone PZ2 are not included in themanagement information recording/reproduction area because recording andreproduction are not performed therein.

Preventing the management information recording/reproduction area fromoverlapping with the OPC area at a position closer to the disk substrate201 than this OPC area is for the purpose of proper recording andreproducing in the management information recording/reproduction area.

As described above, transmittance variation indeterminately occurs inthe OPC area. Because of the influence thereof, if the managementinformation recording/reproduction area overlapping with the OPC areaexists at a position closer to the disk substrate 201 than this OPCarea, laser irradiation with a proper amount of light for thismanagement information recording/reproduction area is impossible andrecording/reproduction operation therein is unstable. To avoid thisproblem, the management information recording/reproduction area such asthe TDMA is not disposed on the disk substrate 201 side of the OPC area.

(P5) Only one management information recording/reproduction area ispermitted to exist at a position closer to the laser-incident surfacethan the OPC area.

As described above, transmittance variation occurs due torecording/reproduction to/from the recording layer. Therefore, foraccurate OPC operation, it is preferred that an area where recording isperformed does not exist at a position closer to the laser-incidentsurface than the OPC area. However, the existence of such an area ispermitted in the existing double-layer disk. For example, in FIG. 12,TDMA#2 is disposed at a position closer to the laser-incident surfacethan OPC(L0).

This is because of the following reason. In the management informationrecording/reproduction area, recording/reproduction is performed withproper laser power, and therefore the accompanying transmittancevariation falls within the predicted range. Thus, this transmittancevariation does not have much influence on the test write in the OPC areaon the back side of the management information recording/reproductionarea.

However, a multi-layer disk such as a triple-layer disk and aquadruple-layer disk involves a possibility that two or more managementinformation recording/reproduction areas are disposed at positionscloser to the laser-incident surface than the OPC area. If pluralmanagement information recording/reproduction areas overlap with the OPCarea and each of these areas is in the recorded state or unrecordedstate, the transmittance of these areas from the viewpoint of the OPCarea on the back side of these areas is unpredictable.

To avoid this problem, two or more management informationrecording/reproduction areas are not so disposed as to overlap with theOPC area at positions closer to the laser-incident surface than this OPCarea.

(P6) Two INFOs in one layer are separated from each other by at least150 μm.

Because it is prescribed that two INFOs in one layer are separated fromeach other by at least 150 μm, which is the allowable defect size, thetriple-layer disk also obeys this prescription.

The inner zone layout developed for the triple-layer disk (BD-R) withattention paid to the above-described points P1 to P6 is as shown inFIG. 13. FIG. 14 shows the start radial position and the number ofclusters of each area.

In layer L0, subsequent to the BCA and the protection zone PZ1, the PICis disposed on the outer circumference side. The PIC has the sizecorresponding to the data capacity for fivefold writing in accordancewith the above-described point P3. The BCA, the protection zone PZ, andthe PIC serve as the reproduction-only area.

Subsequent to the PIC, the protection zone PZ2, the buffer area BUF,INFO#2, OPC(L0), TDMA#1, and INFO#1 are disposed along the directiontoward the outer circumference.

In layer L1, only the BCA and the protection zone PZ1 serve as thereproduction-only area. Subsequent to the protection zone PZ1, thebuffer area BUF, OPC(L1), the reserve area RSV, INFO#4, TDMA#2, thereserve area RSV, and INFO#3 are disposed along the direction toward theouter circumference.

Also in layer L2, only the BCA and the protection zone PZ1 serve as thereproduction-only area. Subsequent to the protection zone PZ1, thebuffer area BUF, OPC(L2), the reserve area RSV, INFO#6, TDMA#3, thebuffer area BUF, and INFO#5 are disposed along the direction toward theouter circumference.

The radial position and the number of clusters of each area will beapparent from reference to FIG. 14.

For this inner zone layout of FIG. 13, the above-described points P1 toP6 are taken into consideration.

As point P1, the BCA, the protection zone PZ1, and the inner zonetermination are fixed. Based on this feature, the PIC, the OPC, theTDMA, the INFO, and so forth are arranged in the radial position rangeof 22.5 mm to 24.0 mm.

As point P3, the PIC capacity, the TDMA capacity, and the OPC size arefollowed.

As point P6, separation by at least 150 μm is ensured between INFO#1 andINFO#2 in layer L0, between INFO#3 and INFO#4 in layer L1, and betweenINFO#5 and INFO#6 in layer L2.

As point P2, overlapping of the OPC areas in the layer direction isavoided.

As shown in FIG. 13, OPC(L2) and OPC(L1) have a gap distance G1therebetween along the radial direction to thereby be prevented fromoverlapping with each other.

Furthermore, a gap distance G2 is set between OPC(L1) and INFO#2 inlayer L0. Thus, OPC(L1) and OPC(L0) are also prevented from overlappingwith each other by the intermediary of the gap distance G2 or longeralong the radial direction.

The gap distances G1 and G2 are 222 μm in the example of the radialposition setting of FIG. 14.

A description will be made below about why the arrangement setting withthe gap distances G1 and G2 can avoid overlapping of the OPC areas inthe layer direction.

As described above, the groove patterns for forming the tracks in layersL0, L1, and L2 are each shaped by a corresponding one of the stampers atthe time of the fabrication of the disk substrate 201 and at the time ofthe formation of the intermediate layer 204. Thus, it is difficult tomake the center points of the groove patterns serving as the trackscompletely match each other, and a predetermined tolerance is permitted.

As shown in FIG. 15( a), a maximum of 75 μm is permitted as the amountof eccentricity of each recording layer. Furthermore, as the radialposition accuracy, a maximum of 100 μm in the absolute value ispermitted as the error of the position of the radius 24 mm of eachrecording layer. For example, it is enough that, on the basis of theposition of the radius 24 mm in layer L0, the error of the position ofthe radius 24 mm in the other layers is smaller than 100 μm.

In this case, the mutual positional offset among the respectiverecording layers is 175 μm in the worst case.

However, defocus needs to be also taken into consideration. As shown inFIG. 15( b), layer L2, which is the recording layer closest to thelaser-incident surface in the triple-layer disk, is separate from layerL0 by a distance slightly shorter than 50 μm. Suppose that this distanceis 46.5 μm for example. In this case, when recording to layer L0 isperformed with focus on layer L0, the laser irradiation range of layerL2 is a range of radius 29 μm.

In consideration of the above-described characteristics, the possibilityof overlapping of the OPC areas arises unless a gap distance of about200 μm or longer is ensured.

In the present example, 222 μm is ensured as each of the gap distancesG1 and G2 by arranging the respective areas as shown in FIG. 13 and FIG.14.

Thus, OPC(L2) and OPC(L1) do not overlap with each other in the layerdirection even when layers L1 and L2 are formed with the maximum offsetin the allowable range. Similarly, OPC(L1) and OPC(L0) also do notoverlap with each other even in the worst case.

Therefore, the condition of point P2 can be completely satisfied, whichcan ensure proper OPC operation in each OPC area.

The condition of point P4, i.e. the condition that the managementinformation recording/reproduction area is not so disposed as to overlapwith the OPC area at a position closer to the disk substrate 201 thanthis OPC area, is also satisfied.

As shown in FIG. 13, on the disk substrate 201 side of OPC(L2), thebuffer area BUF in layer L1 and the PIC in layer L0 are disposed andthus no management information recording/reproduction area exists.

Furthermore, on the disk substrate 201 side of OPC(L1), the PIC, theprotection zone PZ2, and the buffer area BUF in layer L0 are disposedand thus no management information recording/reproduction area exists.Even if the maximum offset within the above-described tolerance occursbetween layers L1 and L0, INFO#2 is never located on the disk substrate201 side of OPC(L1) because the gap distance G2 is 222 μm.

Consequently, no management information recording/reproduction area isdisposed on the back side (on the disk substrate 201 side) of the OPCarea. This avoids a problem that the recording/reproducing operation inthe management information recording/reproduction area is unstabledepending on the recording status of the OPC area.

The condition of point P5, i.e. the condition that only one managementinformation recording/reproduction area is permitted to exist at aposition closer to the laser-incident surface than the OPC area, is alsosatisfied.

This point becomes a matter of concern when the arrangement in layers L1and L2 from the viewpoint of OPC(L0) in layer L0 is considered. This isbecause it is impossible that two or more management informationrecording/reproduction areas are disposed at positions closer to thelaser-incident surface than OPC(L1) and OPC(L2).

At positions closer to the laser-incident surface than OPC(L0), TDMA#2in layer L1 and the buffer area BUF in layer L2 are disposed. Thus, themanagement information recording/reproduction area closer to thelaser-incident surface than OPC(L0) is only TDMA#2.

If the maximum offset within the allowable tolerance exists, INFO#4 andthe reserve area RSV in layer L1 possibly overlap with OPC(L0) in thelayer direction. However, because the gap distance G2 is 222 μm, TDMA#3in layer L2 never overlaps with OPC(L0) in the layer direction.Moreover, a gap distance G3 in FIG. 13 is 235 μm in the design of FIG.14. Thus, INFO#5 in layer L2 also never overlaps with OPC(L0) in thelayer direction.

Consequently, even in the worst case within the allowable tolerance, twoor more management information recording/reproduction areas never existat positions closer to the laser-incident surface than the OPC area.

As described above, the triple-layer disk of the present embodiment isallowed to have a proper layout satisfying the conditions of points P1to P6 by employing the inner zone layout like that of FIG. 13 and FIG.14 for example.

The main points of the triple-layer disk of the present example are asfollows.

-   -   This triple-layer disk is a recordable disk as a plural-layer        disk obtained by providing three recording layers (layers L0 to        L2) over the disk substrate 201 and forming the        optically-transparent layer 203 on the laser-incident surface        side.    -   In each of the recording layers (layers L0 to L2), the test area        for laser power control (OPC(L0), OPC(L1), OPC(L2)) is provided        in the inner zone closer to the inner circumference than the        data zone, in which user data is recorded.    -   The test areas (OPC(L0), OPC(L1), OPC(L2)) in the respective        recording layers (layers L0 to L2) are so disposed as to be        prevented from overlapping with each other in the layer        direction.    -   In the inner zones of the respective recording layers (layers L0        to L2), the management information recording/reproduction areas        where recording and reproduction of management information are        performed are provided.    -   The management information recording/reproduction areas are so        disposed that, for each of the test areas (OPC(L0), OPC(L1),        OPC(L2)) in the respective recording layers, the number of        management information recording/reproduction areas overlapping        with the test area in the layer direction at a position closer        to the laser-incident surface than this test area is equal to or        smaller than one.    -   The management information recording/reproduction areas are so        disposed as to be prevented from overlapping with the test areas        (OPC(L0), OPC(L1), OPC(L2)) in the respective recording layers        in the layer direction on the disk substrate 201 side of the        test areas.

The example of FIG. 13 is shown regarding the BD-R, which is awrite-once disk. In the case of the BD-RE as a rewritable disk, theinner zone layout can be designed as shown in FIG. 16.

The layout of FIG. 16 is obtained by replacing the TDMA in FIG. 13 bythe reserve area RSV. The size of each area is the same as that shown inFIG. 14. The position of the TDMA in FIG. 14 can be treated as that ofthe reserve area RSV.

As described above, the TDMA is used for sequential updating of the TDFLand the space bitmap and so forth for data rewriting and alternationprocessing until final closing processing. In a rewritable disk allowingdata rewriting, the TDMA is unnecessary because the DMA in the INFO canbe rewritten directly.

Therefore, the layout shown in FIG. 16, obtained by replacing the TDMAin FIG. 13 by the reserve area RSV, can be employed. Of course, thislayout satisfies the conditions of points P1 to P6.

By such an inner zone layout, test write and recording/reproduction ofmanagement information in the inner zone can be properly performed alsoin the BD-RE.

[6. Inner Zone of Quadruple-Layer Disk of Embodiment]

The inner zone of the quadruple-layer disk of the embodiment will bedescribed below.

This quadruple-layer disk realizes capacity of about 32 GB per one layerdue to increase in the recording density. An inner zone layout properfor this case is necessary.

The points to which attention is paid in the development of thequadruple-layer disk of the embodiment are the same as theabove-described points P1 to P6. However, in the quadruple-layer disk,satisfaction of the conditions of points P1 to P6 cannot be simplyachieved because of the following reasons.

First, also in the quadruple-layer disk, the PIC, the OPC, the TDMA, andso forth are disposed in the radial position range of 22.5 mm to 24.0 mmfor obedience to point P1. Furthermore, in accordance with point P3, thecapacity of the OPC area, the TDMA, and so forth is ensured similarly.

Specifically, the size of the OPC area is set to 2048 clusters in eachlayer.

The size of the TDMA is 2048 clusters per one layer. Therefore, althoughthe arrangement positions thereof may be in any recording layer,2048×4=8192 clusters are ensured as a whole. Furthermore, the TDMA is sodisposed that the capacity thereof is as even as possible in therecording layers in which the TDMA can be disposed.

However, if the layout is based on this premise as it is, the state inwhich the gap distances G1 and G2 between the OPC areas are set to atleast 200 μm cannot be kept.

This possibly causes the situation in which the condition of point P2that the OPC areas do not overlap with each other in the layer directioncannot be kept even when the offset among the respective layers iswithin the tolerance. That is, possibly the condition of point P2 is notsatisfied.

Therefore, in the case of the quadruple-layer disk, an idea of OPC pairsand an idea of tolerance reduction are employed to address this problem.

First, the inner zone layout developed for the quadruple-layer disk(BD-R) of the present example will be described with FIG. 17. The startradial position and the number of clusters of each area are shown inFIG. 18.

In layer L0, subsequent to the BCA and the protection zone PZ1, the PICis disposed on the outer circumference side. The PIC has the sizecorresponding to the data capacity for fivefold writing in accordancewith the above-described point P3. The BCA, the protection zone PZ, andthe PIC serve as the reproduction-only area.

Subsequent to the PIC, the protection zone PZ2, the buffer area BUF,INFO#2, OPC(L0), the buffer area BUF, and INFO#1 are disposed along thedirection toward the outer circumference.

In layer L1, only the BCA and the protection zone PZ1 serve as thereproduction-only area. Subsequent to the protection zone PZ1, thebuffer area BUF, OPC(L1), INFO#4, TDMA#1, the buffer area BUF, andINFO#3 are disposed along the direction toward the outer circumference.

Also in layer L2, only the BCA and the protection zone PZ1 serve as thereproduction-only area. Subsequent to the protection zone PZ1, thebuffer area BUF, INFO#6, TDMA#2, the buffer area BUF, OPC(L2), TDMA#3,and INFO#5 are disposed along the direction toward the outercircumference.

Also in layer L3, only the BCA and the protection zone PZ1 serve as thereproduction-only area. Subsequent to the protection zone PZ1, OPC(L3),the buffer area BUF, INFO#8, TDMA#4, and INFO#7 are disposed along thedirection toward the outer circumference.

The radial position and the number of clusters of each area will beapparent from reference to FIG. 18.

In this case, the inner zone layout obeys points P1, P3, and P6.

As point P1, the BCA, the protection zone PZ1, and the inner zonetermination are fixed. Based on this feature, the PIC, the OPC, theTDMA, the INFO, and so forth are arranged in the radial position rangeof 22.5 mm to 24.0 mm.

As point P3, the PIC capacity, the TDMA capacity, and the OPC size arefollowed.

The TDMA is so disposed that the capacity is even among layers L1, L2,and L3, in which the TDMA can be disposed. This point will be describedlater as additional points P7 and P8.

As point P6, separation by at least 150 μm is ensured between INFO#1 andINFO#2 in layer L0, between INFO#3 and INFO#4 in layer L1, betweenINFO#5 and INFO#6 in layer L2, and between INFO#7 and INFO#8 in layerL3.

A description will be made below about how to satisfy the conditions ofpoints P2 (the OPC areas do not overlap with each other), P4 (themanagement information recording/reproduction area is not disposed at aposition closer to the disk substrate 201 than the OPC area), and P5(two or more management information recording/reproduction areas are notdisposed at positions closer to the laser-incident surface than the OPCarea).

First, the idea of OPC pairs, i.e. a first OPC pair and a second OPCpair shown in FIG. 17, will be described below.

FIG. 19 shows the OPC areas in the respective layers.

The quadruple-layer disk of the present example is based on theassumption that the so-called opposite track path is employed. This issuch a track path that the traveling direction of recording/reproduction(the traveling direction of the address) is alternately reversed fromlayer to layer. Specifically, the traveling direction is from the innercircumference toward the outer circumference in layer L0, from the outercircumference toward the inner circumference in layer L1, from the innercircumference toward the outer circumference in layer L2, and from theouter circumference toward the inner circumference in layer L3. In FIG.19, the track path direction is shown by arrowheads OTP.

Such a track path that the recording/reproduction direction is from theinner circumference toward the outer circumference in all the layers isreferred to as the parallel track path. The concept of the presentembodiment to be described below can be employed also for the paralleltrack path.

As shown in FIG. 19, OPC(L0) and OPC(L2), which are two OPC areasdisposed closer to the outer circumference in the inner zone, aredefined as the first OPC pair.

Furthermore, OPC(L1) and OPC(L3), which are two OPC areas disposedcloser to the inner circumference, are defined as the second OPC pair.

It is prescribed that the OPC area is consumed in the opposite directionof the recording/reproduction direction (track path). This is because ofthe following reason. In the OPC area, test write is performed withvery-high laser power, and thus the OPC area is often partially damaged.Therefore, if the addresses are used from the smaller address side,possibly the OPC execution position cannot be accessed at the time ofOPC operation.

Thus, in every test write, the OPC area is used from the larger addressside by a predetermined number of sectors used in the test write.Arrowheads OU in the diagram indicate the consumption direction of theOPC area.

Therefore, in the case of the opposite track path, OPC(L0) and OPC(L2)are consumed from the outer circumference side by the predeterminednumber of sectors sequentially in every test write, whereas OPC(L1) andOPC(L3) are consumed from the inner circumference side by thepredetermined number of sectors sequentially in every test write.

The consumption direction OU is the same between two OPC areas in thepair.

Regarding two OPC areas in each pair, the apparent gap distance isconsidered. Specifically, a gap distance AB1 relating to OPC(L0) andOPC(L2) and a gap distance AB2 relating to OPC(L1) and OPC(L3) areconsidered.

The apparent gap distances AB1 and AB2 are the gap distance between thebeginnings of the parts to be used next in the OPC areas (the positionsto be consumed in the next OPC operation). In general, the apparent gapdistances AB1 and AB2 are the gap distance between the beginnings of theunused parts that have not yet been consumed in the OPC areas. Thebeginning of “the part to be used next” is equivalent to the addressindicated as the OPC operation executable address (Next available Ln OPCAddress) in the above-described TDDS.

If it is supposed that the part indicated by the length of the arrowheadOU has been already consumed by the OPC operation in each OPC area, theapparent gap distances AB1 and AB2 are as shown in the diagram.

If the apparent gap distances AB1 and AB2 are ensured, such a virtualgap distance that the purpose of the above-described point P2 (the OPCareas do not overlap with each other) is fulfilled can be achieveddepending on the way of use of the OPC areas.

For example, if OPC(L0) and OPC(L2) are consumed as shown by thearrowheads OU in the first OPC pair in FIG. 19, the OPC positions to beused next do not overlap with each other. However, if the maximumtolerance is taken into consideration and for example the amount ofconsumption of OPC(L2) is significantly larger than that of OPC(L0),possibly the OPC areas practically overlap with each other.

This point will be described below with FIG. 20 by taking the first OPCpair as an example.

FIG. 20( a) shows the assumption of a layout in which no gap distance isset between OPC(L0) and OPC(L2) along the radial direction.

The radial size of the OPC area composed of 2048 clusters is about 250μm.

Even if no gap distance is set as shown in FIG. 20( a), OPC(L0) andOPC(L2) do not overlap with each other in the layer direction in theideal state.

However, if a tolerance of about 200 μm is permitted as described aboveand the offset between layers L0 and L2 is the maximum, overlappingoccurs in a range of about 200 μm as shown in FIG. 20( b).

However, if the above-described apparent gap distance AB1 is taken intoconsideration, the state in which the positions to be used for OPCrecording do not overlap with each other can be achieved even when theoverlapping in the layer direction occurs as shown in FIG. 20(b). Forexample, if OPC(L0) and OPC(L2) are always consumed almost evenly asshown by the dashed-line arrowheads in the diagram, the apparent gapdistance AB1 is always ensured (the apparent gap distance AB1 isequivalent to the gap distance between the tips of the respectivedashed-line arrowheads).

However, the amounts of consumption of the respective OPC areas are notnecessarily even. Although the consumption of OPC(L0) proceeds faster inmany cases, the consumption of OPC(L2) often proceeds faster dependingon the case. In the case of FIG. 20( b), if the amount of consumption ofOPC(L2) becomes twice that of OPC(L0), the apparent gap distance AB1becomes zero.

This is a rare case occurring when the offset between layers L0 and L2is the maximum within the tolerance and the balance of consumptionbetween OPC(L0) and OPC(L2) becomes considerably low. However, thepossibility of the occurrence of such a situation should be as low aspossible.

The tolerance will be reviewed below.

FIG. 21( a) shows the condition in which the maximum tolerance is set toabout 200 μm in the above-described triple-layer disk.

This condition will be reviewed. First, the amount of eccentricity is amatter of the disk manufacturing and it is difficult to set it smallerthan 75 μm. Furthermore, 29 μm as the defocus can also not be changed.

Therefore, as shown in FIG. 21( b), the radial position accuracy is sodefined that the maximum error is 50 μm in the relative value at theposition of a radius of 24 mm. In the case of the triple-layer disk, theabsolute-value error from the reference layer is employed. However, inpractice, the offset of the layers has a relative influence among therespective layers. Thus, the allowable tolerance is changed.Specifically, the offset among the layers is permitted as long as theoffset at the position of a radius of 24 mm between two layers havingthe largest offset among four layers is within the range of 50 μm.

In this case, the maximum tolerance can be estimated to be about 150 μm.Therefore, the quadruple-layer disk is based on the premise that theoffset among the respective layers is equal to or smaller than 150 μmeven in the worst case.

In this case, when the offset between layers L0 and L2 is the largest,overlapping occurs in a range of about 150 μm as shown in FIG. 20( c).This state is better than the state of FIG. 20( b). That is, thepossibility that the apparent gap distance AB1 becomes zero when theamount of consumption of OPC(L2) becomes larger than that of OPC(L0) canbe decreased.

A consideration will be made below about how to further decrease thepossibility that the apparent gap distance AB1 becomes zero.

First, the inter-pair gap distance between the first OPC pair and thesecond OPC pair will be considered.

Because the maximum tolerance is set to 150 μm, it is enough that thegap distance between the pairs, i.e. a gap distance Gp between theinnermost circumference side of OPC(L0) in FIG. 17 and the outermostcircumference side of OPC(L1), is at least 150 μm.

This is because, when the gap distance Gp is at least 150 μm, OPC(L0)and OPC(L1) do not overlap with each other in the layer direction evenif the offset between layers L0 and L1 is the largest.

In the case of the arrangement shown in FIG. 17 and FIG. 18, this gapdistance Gp is 153 μm.

The next consideration will be made below about OPC(L3) in terms ofpoint P4 (the management information recording/reproduction area is notdisposed at a position closer to the disk substrate 201 than the OPCarea).

In FIG. 17, at positions closer to the disk substrate 201 than OPC(L3),the buffer area BUF in layer L2, the buffer area BUF in layer L1, andthe PIC in layer L0 are disposed and thus no management informationrecording/reproduction area exists.

However, in consideration of the offset of the layers, INFO#6 in layerL2 needs to be sufficiently separate in the radial direction. That is agap distance Gf2 in FIG. 17.

In this case, the gap distance Gf2 needs to be at least 200 μm if themaximum tolerance is set to 200 μm. In contrast, if the maximumtolerance is set to 150 μm as described above, it is enough that the gapdistance Gf2 is at least 150 μm. In the case of the arrangement shown inFIG. 17 and FIG. 18, this gap distance Gf2 is 153 μm.

Furthermore, attention will be paid to OPC(L0) in terms of point P5 (twoor more management information recording/reproduction areas are notdisposed at positions closer to the laser-incident surface than the OPCarea).

Only TDMA#1 in layer L1 is disposed as the management informationrecording/reproduction area closer to the laser-incident surface thanOPC(L0). However, if the offset of the layers is taken intoconsideration, the positional relationship between TDMA#1 in layer L1and INFO#8 in layer L3 becomes a matter of concern. That is a gapdistance Gtf in FIG. 17.

Also in this case, the gap distance Gtf needs to be at least 175 μm ifthe maximum tolerance except for the error due to defocus is set to 175μm. However, if the maximum tolerance except for the error due todefocus is set to 125 μm, it is enough that the gap distance Gtf isabout 125 μm. In the case of the arrangement shown in FIG. 17 and FIG.18, this gap distance Gtf is 145 μm.

The reason why the error due to defocus can be excluded from the maximumtolerance regarding the gap distance Gtf is as follows. Referring toFIG. 15( b), even if layer L1 and layer L2 have been recorded from theleft side and the right side to the one-dot chain line in the diagram,the influence on layer L0 is caused by one layer as a whole, i.e. eachof layer L1 and layer L2 causes half of the influence.

As just described, the gap distances Gf2 and Gtf do not need to be atleast 200 μm and 175 μm, respectively, but it is enough that the gapdistances Gf2 and Gtf are at least 150 μm and 125 μm, respectively. Thismeans that each of the gap distances Gf2 and Gtf can be decreased by 50μm by setting the tolerance to 150 μm.

In this case, the margin of each 50 μm can be applied to gap distancesGi1 and Gi2 in the respective OPC pairs.

Because of the above-described characteristics, as shown in FIG. 20( d),a gap distance of 50 μm can be set in the arrangement of OPC(L0) andOPC(L2) in the pair (this gap distance is equivalent to the gap distanceGi1 in FIG. 17).

In this case, when the offset between layers L0 and L2 is the largest,overlapping occurs in a range of about 100 μm as shown in FIG. 20( e).This state is further better than the state of FIG. 20( c).

That is, the possibility that the apparent gap distance AB1 becomes zerois low even when the amount of consumption of OPC(L2) becomesconsiderably larger than that of OPC(L0).

In practice, even in the worst case, the disappearance of the apparentgap distance AB1 can be mostly avoided.

In addition, it is possible that the use of the OPC area is adjustedthrough processing of OPC(L2) and OPC(L0) on the recording device sideso that the disappearance of the apparent gap distance AB1 can beprevented. This characteristic will be described later with FIG. 25 andFIG. 26.

Based on the above-described characteristics, the gap distance Gi1 isset between OPC(L2) and OPC(L0) of the first OPC pair, and the gapdistance Gi2 is set between OPC(L3) and OPC(L1) of the second OPC pair.In the case of the arrangement shown in FIG. 17 and FIG. 18, the gapdistances Gi1=G12=57 μm.

Due to this setting, the apparent gap distances AB1 and AB2 shown inFIG. 19 are ensured, and overlapping between OPC(L2) and OPC(L0) andbetween OPC(L3) and OPC(L1) in the layer direction are avoidedvirtually.

Furthermore, the gap distance Gp of 153 μm is set between the innermostcircumference side of OPC(L0) and the outermost circumference side ofOPC(L1) as described above. Thus, overlapping between OPC(L0) andOPC(L1) in the layer direction also never occurs even when the offset ofthe layers is the largest within the tolerance.

Therefore, the layout of FIG. 17 and FIG. 18 satisfies the condition ofpoint P2 (the OPC areas do not overlap with each other) virtually.

Verification about point P4 (the management informationrecording/reproduction area is not disposed at a position closer to thedisk substrate 201 than the OPC area) is as follows.

For OPC(L3), the management information recording/reproduction area isnot disposed on the disk substrate 201 side thereof as described above.

As for OPC(L2), on the disk substrate 201 side thereof, the buffer areaBUF in layer L1 and the buffer area BUF in layer L0 are located and thusno management information recording/reproduction area exists. The areasthat should be considered in terms of the offset of the layers areINFO#1 in layer L0 and INFO#3 in layer L1. However, as is apparent fromthe description made thus far, it is enough that a gap distance G13shown in FIG. 17 is at least 150 μm. In the case of the arrangementshown in FIG. 17 and FIG. 18, the gap distance Gi3 is 153 μm. Thus, themanagement information recording/reproduction area is never located onthe disk substrate 201 side of OPC(L2).

As for OPC(L1), on the disk substrate 201 side thereof, the PIC in layerL0 is located and thus no management information recording/reproductionarea exists. The area that should be considered in terms of the offsetof the layers is INFO#2 in layer L0. However, it is enough that a gapdistance Gf1 is at least 150 μm similarly to the above description. Inthe case of the arrangement shown in FIG. 17 and FIG. 18, the gapdistance Gf2 is 153 μm. Thus, the management informationrecording/reproduction area is never located on the disk substrate 201side of OPC(L1).

From the above-described facts, the condition of point P4 is alsosatisfied.

Verification about point P5 (two or more management informationrecording/reproduction areas are not disposed at positions closer to thelaser-incident surface than the OPC area) is as follows.

The subject of the verification is the positions of OPC(L0) and OPC(L1)in the layer direction. For OPC(L0), there is no problem as describedabove.

As for OPC(L1), on the laser-incident surface side thereof, INFO#6 andTDMA#2 in layer L2 and the buffer area BUF in layer L3 exist. Thus,there is no problem.

That is, the condition of point P5 is satisfied.

As is apparent from FIG. 17 and FIG. 18, the TDMA is not disposed inlayer L0. This is a technique to satisfy the conditions of point P4 andpoint P5 and ensure as long the gap distances Gi1 and Gi2 as possible.As described above, the TDMAs of the respective recording layers arecollectively used as one large TDMA, and therefore the TDMA does nothave to be disposed in all the recording layers.

In consideration of the layout of the quadruple-layer disk, emphasis isplaced on the overlapping of the OPC areas in the layer direction andthe TDMA is removed from the recording layer closest to the disksubstrate.

This is defined as additional point P7 for the quadruple-layer disk andreference thereto will be made hereinafter.

Furthermore, seeing FIG. 17 and FIG. 18 regarding the TDMA will make itapparent that the sizes of the TDMAs in layers L1 to L3 are almost equalto each other. If the TDMA is disposed in one recording layer, e.g.layer L3, in a concentrated manner, OPC(L3) is consumed by recordingadjustment for layer L3 for updating of the TDMA.

Therefore, it is preferable to allocate the TDMA to the respectiverecording layers as evenly as possible so that imbalance of the OPC areaconsumption can be prevented.

In the present embodiment, the TDMA can be regarded as being almostevenly allocated if the TDMA allocation size in the recording layerhaving the largest allocation size is equal to or smaller than twicethat in the recording layer having the smallest allocation size.

This is defined as additional point P8 for the quadruple-layer disk andreference thereto will be made hereinafter.

As described above, the quadruple-layer disk of the present example isallowed to have a proper layout satisfying the conditions of points P1to P8 by employing the inner zone layout like that shown in FIG. 17 andFIG. 18 for example.

The main points of the quadruple-layer disk of the present example areas follows.

-   -   This quadruple-layer disk is a recordable optical disk obtained        by providing four recording layers (layers L0 to L3) over the        disk substrate 201 and forming the optically-transparent layer        203 on the laser-incident surface side.    -   In the recording layers (layers L0 to L3), OPC(L0), OPC(L1),        OPC(L2), and OPC(L3) are provided as the test area for laser        power control in the inner circumference side area (inner zone)        closer to the inner circumference than the data zone, in which        user data is recorded. Thus, the quadruple-layer disk has four        test areas.    -   Of four test areas, two test areas closer to the disk outer        circumference (OPC(L0) and OPC(L2)) are defined as the first OPC        pair, and two test areas closer to the disk inner circumference        (OPC(L1) and OPC(L3)) are defined as the second OPC pair. The        test areas forming the first OPC pair and the test areas forming        the second OPC pair are so disposed as to be prevented from        overlapping with each other in the layer direction.    -   Two test areas of the first OPC pair (OPC(L0) and OPC(L2)) have        the same consumption direction of the test area. Furthermore,        the respective test areas are so disposed that the parts to be        used next in the test areas are prevented from overlapping with        each other in the layer direction by the intermediary of the        apparent gap distance AB1.    -   Two test areas of the second OPC pair (OPC(L1) and OPC(L3)) have        the same consumption direction of the test area opposite to the        consumption direction of the test area in the first OPC pair        (however, they have the same consumption direction as that of        the test area in the first OPC pair if the above-described        parallel track path is employed). Furthermore, the respective        test areas (OPC(L1) and OPC(L3)) are so disposed that the parts        to be used next in the test areas are prevented from overlapping        with each other in the layer direction by the intermediary of        the apparent gap distance AB2.    -   In the above-described inner circumference side area in each        recording layer, the management information        recording/reproduction areas for recording and reproduction of        management information are provided. As the total size thereof,        the size obtained by multiplying the management information size        of the existing single-layer disk by the number of layers is        ensured.    -   The management information recording/reproduction areas are so        disposed that, for each of the test areas (OPC(L0), OPC(L1),        OPC(L2), OPC(L3)) in the respective recording layers (layers L0        to L3), the number of management information        recording/reproduction areas overlapping with the test area in        the layer direction at a position closer to the laser-incident        surface than this test area is equal to or smaller than one.    -   The management information recording/reproduction areas are so        disposed as to be prevented from overlapping with the test areas        (OPC(L0), OPC(L1), OPC(L2), OPC(L3)) in the respective recording        layers in the layer direction on the disk substrate 201 side of        the test areas.    -   Emphasis is placed on the overlapping of the OPC areas in the        layer direction and the TDMA is removed from the recording layer        (layer L0) closest to the disk substrate.    -   The TDMA is allocated to the recording layers in which the TDMA        is disposed with as even size as possible.

To be more specific for the practical arrangement, the following mainpoints can be cited.

-   -   The quadruple-layer disk of the present example is an optical        disk having a diameter of 12 cm. The respective test areas        (OPC(L0), OPC(L1), OPC(L2), OPC(L3)) are formed with a radial        width of about 250 μm in the radial position range of 22.5 mm to        24.0 mm of the optical disk.    -   The respective recording layers (layers L0 to L3) are so formed        that the relative error in the radial position of the layers is        within the tolerance of about 150 μm.    -   The innermost circumference radial position of the test areas        forming the first OPC pair (the innermost circumference side of        OPC(L0)) and the outermost circumference radial position of the        test areas forming the second OPC pair (the outermost        circumference side of OPC(L1)) are disposed at positions that do        not overlap with each other in the layer direction but have the        gap distance Gp of at least about 150 μm along the radial        direction if the above-described relative error in the radial        position is considered as zero.    -   Two test areas of the first OPC pair (OPC(L0) and OPC(L2)) are        formed at positions that do not overlap with each other in the        layer direction but have the gap distance Gi1 of at least about        50 μm along the radial direction if the above-described relative        error in the radial position is considered as zero.    -   Two test areas of the second OPC pair (OPC(L1) and OPC(L3)) are        formed at positions that do not overlap with each other in the        layer direction but have the gap distance Gi2 of at least about        50 μm along the radial direction if the above-described relative        error in the radial position is considered as zero.    -   The TDMA is not disposed in layer L0 but disposed in layers L1        to L3 with even size.

The example of FIG. 17 is shown regarding the BD-R, which is awrite-once disk. In the case of the BD-RE as a rewritable disk, theinner zone layout can be designed as shown in FIG. 22.

The layout of FIG. 22 is obtained by replacing the TDMA in FIG. 17 bythe reserve area RSV. The size of each area is the same as that shown inFIG. 18. The position of the TDMA in FIG. 18 can be treated as that ofthe reserve area RSV.

As described above, the TDMA is used for sequential updating of the TDFLand the space bitmap and so forth for data rewriting and alternationprocessing until final closing processing. In a rewritable disk allowingdata rewriting, the TDMA is unnecessary because the DMA in the INFO canbe rewritten directly.

Therefore, the layout shown in FIG. 22, obtained by replacing the TDMAin FIG. 17 by the reserve area RSV, can be employed. Of course, thislayout satisfies the conditions of points P1 to P8.

By such an inner zone layout, test write and recording/reproduction ofmanagement information in the inner zone can be properly performed alsoin the BD-RE.

[7. Disk Drive Device]

Next, a description will be made below about a disk drive device(recording/reproduction device) capable of dealing with the triple-layerdisk and the quadruple-layer disk of the present example as e.g. theBD-R and the BD-RE.

The disk drive device of the present example executes format processingfor a disk in which e.g. only the above-described BCA and PIC are formedbut no data is recorded in the recordable area. Thereby, the disk layoutin the state described with FIG. 13 or FIG. 17 can be formed.Furthermore, for such a formatted disk, the disk drive device performsrecording/reproduction of data to/from the user data area. The diskdrive device also performs recording/updating of the TDMA, the ISA, andthe OSA on an as-needed basis.

FIG. 23 shows the configuration of the disk drive device.

A disk 1 is the triple-layer disk or the quadruple-layer disk of theabove-described embodiment. The disk 1 is placed on a turntable (notshown) and is rotationally driven by a spindle motor 52 at a constantlinear velocity (CLV) at the time of recording/reproduction.

An optical pick-up (optical head) 51 reads out management/controlinformation as the ADIP address and pre-recorded information embedded asthe wobbling of the groove track on the disk 1.

At the time of initialization format and at the time of user datarecording, management/control information and user data are recorded inthe track in the recordable area by the optical pick-up 51. At the timeof reproduction, the recorded data is read out by the optical pick-up51.

In the optical pick-up 51, the following components (not shown) areformed: a laser diode serving as the laser light source; a photodetectorfor detecting reflected light; an objective lens serving as the outputterminal of laser light; and an optical system that emits the laserlight to the disk recording surface via the objective lens and guidesreflected light of the laser light to the photodetector.

In the optical pick-up 51, the objective lens is held movably in thetracking direction and the focus direction by a biaxial mechanism.

The whole of the optical pick-up 51 is permitted to move in the diskradial direction by a sled mechanism 53.

The laser diode in the optical pick-up 51 is driven for laser lightemission by a drive signal (drive current) from a laser driver 63.

Reflected-light information from the disk 1 is detected by thephotodetector in the optical pick-up 51, and is converted to anelectrical signal dependent on the amount of received light to besupplied to a matrix circuit 54.

The matrix circuit 54 includes a current-voltage conversion circuit, amatrix calculation/amplification circuit, and so forth for the outputcurrent from plural light-receiving elements as the photodetector, andgenerates the necessary signal by matrix calculation processing.

For example, the matrix circuit 54 generates a high-frequency signalequivalent to reproduction data (reproduction data signal), a focuserror signal and a tracking error signal for servo control, and soforth.

Furthermore, the matrix circuit 54 generates a push-pull signal as asignal relating to the wobbling of the groove, i.e. a signal to detectthe wobbling.

The matrix circuit 54 is integrally formed in the optical pick-up 51 insome cases.

The reproduction data signal output from the matrix circuit 54 issupplied to a reader/writer circuit 55. The focus error signal and thetracking error signal are supplied to a servo circuit 61. The push-pullsignal is supplied to a wobble circuit 58.

The reader/writer circuit 55 executes binarization processing,reproduction clock generation processing by a PLL, and so forth for thereproduction data signal to reproduce the data read out by the opticalpick-up 51 and supply the data to a modulation/demodulation circuit 56.

The modulation/demodulation circuit 56 includes a functional partserving as a decoder at the time of reproduction and a functional partserving as an encoder at the time of recording.

At the time of reproduction, the modulation/demodulation circuit 56executes demodulation processing of the run-length limited code based onthe reproduction clock, as decode processing.

An ECC encoder/decoder 57 executes ECC encode processing of adding theerror correction code at the time of recording, and executes ECC decodeprocessing of performing error correction at the time of reproduction.

At the time of reproduction, the ECC encoder/decoder 57 captures thedata resulting from demodulation by the modulation/demodulation circuit56 into the internal memory and executes error detection/correctionprocessing, deinterleaving processing, and so forth to obtainreproduction data.

The data obtained by the decoding to the reproduction data by the ECCencoder/decoder 57 is read out and transferred to connected apparatussuch as an AV (Audio-Visual) system 120 based on a command by a systemcontroller 60.

The push-pull signal output from the matrix circuit 54 as the signalrelating to the wobbling of the groove is processed in the wobblecircuit 58. The push-pull signal as ADIP information is demodulated intoa data stream forming the ADIP address in the wobble circuit 58 and issupplied to an address decoder 59.

The address decoder 59 decodes the supplied data to obtain an addressvalue and supply it to the system controller 60.

Furthermore, the address decoder 59 generates a clock by PLL processingby use of the wobble signal supplied from the wobble circuit 58, andsupplies the clock to the respective units as e.g. an encode clock atthe time of recording.

Furthermore, as the push-pull signal output from the matrix circuit 54as the signal relating to the wobbling of the groove, the push-pullsignal as pre-recorded information (PIC) is subjected to bandpass filterprocessing in the wobble circuit 58 and then supplied to thereader/writer circuit 55. Subsequently, the signal is binarized to beturned to a data bit stream and thereafter subjected to ECC decode anddeinterleaving in the ECC encoder/decoder 57, so that data as thepre-recorded information is extracted. The extracted pre-recordedinformation is supplied to the system controller 60.

The system controller 60 can execute various kinds of operation settingprocessing, copy protect processing, and so forth based on the readpre-recorded information.

At the time of recording, recording data is transferred from the AVsystem 120. This recording data is sent to a memory in the ECCencoder/decoder 57 and buffered therein.

In this case, the ECC encoder/decoder 57 executes error correction codeaddition, interleaving, and addition of a subcode and so forth as encodeprocessing for the buffered recording data.

The data resulting from the ECC encode is subjected to modulation ofe.g. the RLL (1-7) PP system in the modulation/demodulation circuit 56,and then supplied to the reader/writer circuit 55.

As the encode clock serving as the reference clock for the encodeprocessing at the time of recording, the clock generated from the wobblesignal as described above is used.

The recording data generated by the encode processing is subjected torecording compensation processing by the reader/writer circuit 55. Asthe recording compensation processing, the reader/writer circuit 55carries out e.g. fine adjustment of the optimum recording powerdependent on the characteristics of the recording layer, the spot shapeof the laser light, the recording linear velocity, and so forth andadjustment of the waveform of the laser drive pulse. Thereafter, therecording data is sent to the laser driver 63 as the laser drive pulse.

The laser driver 63 gives the supplied laser drive pulse to the laserdiode in the optical pick-up 51 to carry out laser light emissiondriving. Thereby, the pits corresponding to the recording data areformed on the disk 1.

The laser driver 63 includes a so-called APC circuit (Auto PowerControl) and controls the laser output so that the laser output may bekept constant irrespective of the temperature and so forth whilemonitoring the laser output power based on the output of a detector forlaser power monitoring provided in the optical pick-up 51. The targetvalues of the laser output in recording and reproduction are given fromthe system controller 60, and the laser output level is so controlled asto be at the target value in each of recording and reproduction.

The servo circuit 61 generates various kinds of servo drive signals forfocus, tracking, and sled from the focus error signal and the trackingerror signal from the matrix circuit 54 to make the related componentscarry out servo operation.

Specifically, the servo circuit 61 generates a focus drive signal and atracking drive signal depending on the focus error signal and thetracking error signal to drive a focus coil and a tracking coil of thebiaxial mechanism in the optical pick-up 51. Thereby, a tracking servoloop and a focus servo loop by the optical pick-up 51, the matrixcircuit 54, the servo circuit 61, and the biaxial mechanism are formed.

Furthermore, in response to a track jump command from the systemcontroller 60, the servo circuit 61 turns off the tracking servo loopand outputs a jump drive signal to thereby make the related componentscarry out track jump operation.

In addition, the servo circuit 61 generates a sled drive signal based ona sled error signal obtained as the low-frequency component of thetracking error signal, access execution control from the systemcontroller 60, and so forth, to drive the sled mechanism 53. The sledmechanism 53 has a mechanism formed of a main shaft for holding theoptical pick-up 51, a sled motor, a transmission gear, and so forth,although not shown in the diagram. The sled mechanism 53 drives the sledmotor in accordance with the sled drive signal, and thereby therequisite slide movement of the optical pick-up 51 is performed.

A spindle servo circuit 62 carries out control to cause the CLV rotationof the spindle motor 2.

The spindle servo circuit 62 obtains the clock generated by the PLLprocessing for the wobble signal as information on the presentrotational velocity of the spindle motor 52, and compares theinformation with predetermined CLV reference velocity information tothereby generate a spindle error signal.

At the time of data reproduction, the reproduction clock (clock servingas the basis of decode processing) generated by the PLL in thereader/writer circuit 55 serves as the information on the presentrotational velocity of the spindle motor 52. Thus, it is also possiblefor the spindle servo circuit 62 to generate the spindle error signal bycomparing this information with the predetermined CLV reference velocityinformation.

The spindle servo circuit 62 outputs a spindle drive signal generateddepending on the spindle error signal to cause the CLV rotation of thespindle motor 62.

In addition, the spindle servo circuit 62 generates the spindle drivesignal in response to a spindle kick/brake control signal from thesystem controller 60 to thereby make the spindle motor 2 carry out alsooperation of activation, stop, acceleration, deceleration, etc.

Various kinds of operation of the above-described servo system andrecording/reproduction system are controlled by the system controller 60formed of a microcomputer.

The system controller 60 executes various kinds of processing inresponse to a command from the AV system 120.

For example, when a writing order (write command) is issued from the AVsystem 120, first the system controller 60 makes the optical pick-up 51move to the address to which data should be written. Subsequently, thesystem controller 60 makes the ECC encoder/decoder 57 and themodulation/demodulation circuit 56 execute the encode processing fordata (e.g. video data of any of various systems such as the MPEG2 andaudio data) transferred from the AV system 120 in the above-describedmanner. Subsequently, the laser drive pulse from the reader/writercircuit 55 is supplied to the laser driver 63, and thereby recording isperformed.

For example when a read command for requiring transfer of certain data(e.g. MPEG2 video data) recorded in the disk 1 is supplied from the AVsystem 120, first the system controller 60 carries out seek operationcontrol with the aim of the indicated address. Specifically, the systemcontroller 60 issues a command to the servo circuit 61 to make theoptical pick-up 51 carry out access operation with targeting on theaddress specified by the seek command.

Thereafter, the system controller 60 carries out operation controlnecessary to transfer data of the indicated data leg to the AV system120. That is, the system controller 60 performs data readout from thedisk 1, and makes the reader/writer circuit 55, themodulation/demodulation circuit 56, and the ECC encoder/decoder 57execute decode/buffering and so forth to transfer the requested data.

At the time of recording/reproducing of these data, the systemcontroller 60 can control access and recording/reproduction operation byusing the ADIP address detected by the wobble circuit 58 and the addressdecoder 59.

Furthermore, at a predetermined timing such as the timing of loading ofthe disk 1, the system controller 60 makes the related units performreadout of the unique ID recorded in the BCA of the disk 1 and thepre-recorded information (PIC) recorded in the reproduction-only area asthe wobbling groove.

In this case, first the system controller 60 carries out seek operationcontrol with the aim of the BCA and the PIC. Specifically, the systemcontroller 60 issues a command to the servo circuit 61 to make theoptical pick-up 51 carry out access operation to the disk innermostcircumference side.

Thereafter, the system controller 60 makes the optical pick-up 51perform reproduction tracing to obtain the push-pull signal asreflected-light information, and makes the wobble circuit 58, thereader/writer circuit 55, and the ECC encoder/decoder 57 execute decodeprocessing. Thereby, the system controller 60 obtains reproduction dataas the BCA information and the pre-recorded information.

The system controller 60 carries out laser power setting, copy protectprocessing, and so forth based on the BCA information and thepre-recorded information read out in this manner.

In FIG. 23, a cache memory 60 a is shown in the system controller 60.This cache memory 60 a is utilized for e.g. holding and updating of theTDFL/space bitmap read out from the TDMA in the disk 1.

When the disk 1 is loaded for example, the system controller 60 controlsthe respective units to make them perform readout of the TDFL/spacebitmap recorded in the TDMA, and holds the read information in the cachememory 60 a.

Thereafter, when alternation processing due to data rewriting or adefect is executed, the TDFL/space bitmap in the cache memory 60 a isupdated.

For example, the TDFL or the space bitmap may be additionally recordedin the TDMA in the disk 1 every time alternation processing is executeddue to data writing, data rewriting, or the like and the space bitmap orthe TDFL is updated. However, this scheme consumes the TDMA in the disk1 fast.

To avoid this disadvantage, the TDFL/space bitmap is updated in thecache memory 60 a during the period until the disk 1 is ejected from thedisk drive device for example. At the time of the ejection or the like,the final (latest) TDFL/space bitmap in the cache memory 60 a is writtento the TDMA in the disk 1. Thus, updating on the disk 1 is so performedthat a large number of times of updating of the TDFL/space bitmap areput together. This can reduce the consumption of the TDMA in the disk 1.

In the configuration example of the disk drive device of FIG. 23, thedisk drive device is connected to the AV system 120. However, the diskdrive device according to the embodiment of the present invention may beconnected to e.g. a personal computer.

Alternatively, it is also possible to employ a form in which the diskdrive device is not connected to another device. In this case, the diskdrive device is provided with an operating unit and a display unit, andthe configuration of the interface part for data input/output isdifferent from that in FIG. 23. That is, recording and reproduction areperformed in accordance with the operation by the user, and a terminalpart for input/output of various kinds of data is formed.

Of course, a wide verity of other configuration examples will also bepossible. For example, an example as a recording-only device or areproduction-only device will also be available.

FIG. 24 shows control processing examples of the system controller 60for the operation of the disk drive device.

FIG. 24( a) shows format processing.

When an unformatted disk 1 is loaded and the format processing isexecuted, first the system controller 60 performs disk discrimination tocheck the inner zone layout and grasp the positions of the OPC areas.

A wide verity of methods are available regarding the technique of thedisk discrimination. Although not described in detail here, the numberof recording layers is determined when the disk 1 as the Blu-ray Disc isloaded for example. The following description will deal with processingwhen a triple-layer disk or a quadruple-layer disk is loaded.

The system controller 60 holds, in its internal memory, information onthe area configuration of the inner zone described with FIG. 13 and FIG.14 regarding the triple-layer disk and information on the areaconfiguration of the inner zone described with FIG. 17 and FIG. 18regarding the quadruple-layer disk.

In a step F101, the system controller 60 checks the positions of the OPCareas in the loaded disk 1 (triple-layer disk or quadruple-layer disk)from this information of the area configuration.

In a step F102, the system controller 60 executes OPC controlprocessing. Specifically, the system controller 60 instructs the servocircuit 61 and the spindle circuit 62 to make the optical pick-up 54access the OPC area. Furthermore, the system controller 60 makes thereader/writer circuit 55 supply a signal as an OPC test pattern to thelaser driver 63, and makes the laser driver 63 perform test recording tothe OPC area. Moreover, the system controller 60 performs reproductionfrom the OPC area in which the recording has been performed and obtainsthe evaluation values about a reproduction information signal, such asthe jitter, the asymmetry, and the error rate, to determine the optimumrecording laser power. Then the system controller 60 sets the laserpower to the optimum power.

Thereafter, in a step F103, the system controller 60 controls recordingoperation as the format processing.

For example, the system controller 60 controls execution of e.g.recording operation of recording, in the TDDS, the addresses of thespace bitmap, the TDFL, and so forth in the TDMA that is disposed in therecording layers in which the TDMA can be disposed with as even capacityas possible so that the structure of the TDMA can be grasped from theinformation of the TDDS from then on.

By such format processing, the disk 1 having the format of FIG. 13 orFIG. 17 is allowed to be used from then on.

FIG. 24( b) shows processing at the time of recording.

In recording operation for user data or management information, first ina step F201, the system controller 60 checks information on the TDMA tograsp the necessary items such as the TDDS, the defect list, the spacebitmap, and the OPC area that can be used next.

Next, in a step F202, the system controller 60 makes the related unitscarry out OPC operation by using the OPC area, and sets the optimumrecording laser power from the result of the OPC operation.

In a step F203, the system controller 60 makes the related units carryout recording operation for user data or the like.

After the recording, in a step F204, the system controller 60 updatesthe TDMA. Specifically, the system controller 60 newly records the TDMAresulting from updating of the necessary information among the pieces ofinformation, such as the TDDS, the defect list, the space bitmap, andthe OPC area that can be used next.

FIG. 24( c) shows processing at the time of reproduction.

In a step F301, the system controller 60 grasps various kinds ofmanagement information from read data such as the TDMA and the filesystem.

In a step F302, the system controller 60 makes the optical pick-up 51access the intended address in accordance with a read command from theAV system 120, and makes the related units carry out reproductionoperation in a step F303. Specifically, the system controller 60performs data readout from the disk 1 and makes the reader/writercircuit 55, the modulation/demodulation circuit 56, and the ECCencoder/decoder 57 execute decode/buffering and so forth to transfer therequested data to the AV system 120.

The above description relates to the format processing, the recordingprocessing, and the reproduction processing executed by the disk drivedevice for a triple-layer disk and a quadruple-layer disk.

Processing relating to the OPC operation when the disk 1 is aquadruple-layer disk will be described below.

As described above, in the quadruple-layer disk, the idea of the firstOPC pair and the second OPC pair is introduced for four OPC areas.Furthermore, the apparent gap distance (gap distance between thebeginnings of the parts to be used next) is ensured between two OPCareas in each pair, to thereby prevent the parts used in the OPCoperation from overlapping with each other in the layer direction.

For example, in the above-described layout of FIG. 17 and FIG. 18, theapparent gap distances (AB1 and AB2 in FIG. 19) are usually ensured evenwhen the offset of the layers is the worst within the allowabletolerance. However, for example regarding the first OPC pair, thepossibility of the disappearance of the apparent gap distance (AB1) isnot zero if the amount of consumption of OPC(L2) is too larger than thatof OPC(L0). Thus, it is preferable that the disk drive device side alsohave ingenuity relating to the OPC operation processing for keeping theapparent gap distance.

FIG. 25 and FIG. 26 to be described next each show a processing exampleof the disk drive device side for preventing the occurrence of asituation in which the apparent gap distance between the OPC areas inthe pair disappears for each of the first OPC pair and the second OPCpair.

First, the processing example of FIG. 25 will be described below.

In FIG. 25, initially processing at the time of disk loading is shown assteps F401 to F408. The processing of the steps F401 to F408 issimilarly executed also when the loaded disk 1 is a triple-layer disk.This processing is executed prior to the processing of FIGS. 24( a),(b), and (c) for example.

In the step F401, disk load is carried out. The system controller 60detects disk insertion to control a disk loading mechanism (not shown inFIG. 23) and make the disk 1 enter such a state as to allowrecording/reproduction driving by the optical pick-up 51 and the spindlemotor 52 (chucking state).

In the step F402, servo adjustment is carried out. Specifically, thesystem controller 60 controls the activation of the spindle motor 52 andthe servo start-up of the optical pick-up 51. The system controller 60controls the spindle circuit 62 to obtain settlement to a predeterminedrotational velocity, and controls the servo circuit 61 to make it carryout focus search, focus servo-on, tracking servo-on, and so forth, tothereby achieve the reproducible state.

Upon the completion of the start-up operation described so far, thesystem controller 60 makes the optical pick-up 51 access the PIC area inthe disk 1 in the step F403. In the step F403, the system controller 60makes the related units reproduce data in the PIC area to therebyperform read of PIC information such as the recording conditions of therespective recording layers.

Next, in the step F405, the system controller 60 makes the opticalpick-up 51 access the beginning TDMA. As described above, the TDMAaccess indicator is provided in the beginning TDMA (e.g. TDMA#1 in FIG.17). In the step F406, by making the related units reproduce the TDMAaccess indicator, the system controller 60 can discriminate the in-useTDMA (hereinafter, TDMA_N), in which the latest TDDS and so forth isrecorded.

Subsequently, in the step F407, the system controller 60 makes theoptical pick-up 51 access TDMA_N. In the step F408, the systemcontroller 60 makes the related units reproduce this TDMA_N to read thelatest TDMA data (the latest TDDS and so forth).

The end of the step F408 is equivalent to the completion of themanagement information read at the time of disk loading. From then on,the system controller 60 waits for a command from the host apparatus (AVsystem 120).

As an example in which the OPC processing is executed in response toissuing of a write command, processing of steps F501 to F511 will bedescribed below.

An operation example is also possible in which the OPC operation aboutthe respective recording layers is carried out after the managementinformation read at the time of disk loading even if the issuing of thewrite command is absent.

The OPC processing example of the steps F501 to F511 in FIG. 25 is anexample in which the OPC operation is carried out for each of therespective layers L0 to L3 in response to the write command.

Upon the issuing of the write command, the system controller 60 forwardsthe processing from the step F501 to the step F502, where the systemcontroller 60 grasps the address ADD[n] at which the next OPC operationcan be carried out about the OPC areas in the respective layers. Thisaddress ADD[n] is indicated as the OPC operation executable address(Next available Ln OPC Address) in the above-described TDDS.

About each of the respective OPC areas (OPC(L0), OPC(L1), OPC(L2),OPC(L3)), the system controller 60 grasps the address ADD[n] from thelatest TDDS from which the address ADD[n], at which the next OPCoperation can be carried out, has been already read.

In the step F503, the system controller 60 sets a variable X indicatingthe layer to 0. Subsequently, in the steps F504 to F509, the systemcontroller 60 makes the related units carry out the OPC operation in theOPC areas in the respective layers (OPC(L0), OPC(L1), OPC(L2), OPC(L3)).

In the step F504, the system controller 60 makes the optical pick-up 51access the address ADD[n] of the part to be used next in the OPC area inlayer L(X) (OPC(L(X))).

In the step F505, the system controller 60 checks whether this addressADD[n] is surely unrecorded (i.e. whether the address ADD[n] can be usedfor the OPC operation). For example, the system controller 60 makes therelated units perform reproduction from the address ADD[n] to checkwhether the recording is present or absent at this address ADD[n]. Ifthe part from this address ADD[n] has been used, the system controller60 seeks an unused part and causes movement to this unused part.

In the step F506, the system controller 60 instructs the respectiverequisite units of the recording system (the ECC encoder/decoder 57, themodulation/demodulation circuit 56, the reader/writer circuit 55, thelaser driver 63, and so forth) to execute test write in the part fromthe address ADD[n]. For example, the system controller 60 makes theseunits carry out data recording operation by a predetermined testpattern, random data, or the like with stepwise variation in therecording laser power.

After the end of the test write, in the step F507, the system controller60 makes the part in which the test write has been executed bereproduced by the optical pick-up 51. At this time, the systemcontroller 60 measures the index values (e.g. the jitter, the asymmetry,the error rate, and the SAM value) corresponding to the respectivevalues of the recording laser power, and decides the optimum recordinglaser power.

The system controller 60 increments the variable X in the step F508. Ifthe variable X is equal to or smaller than 3 in the step F509, theprocessing returns to the step F504.

Therefore, the steps F504 to F507 are carried out with increment of thevariable X. That is, the OPC operation is carried out in OPC(L0),OPC(L1), OPC(L2), and OPC(L3) sequentially.

At the timing of the completion of the above-described OPC operation infour OPC areas, the optimum recording laser power has been decided foreach of the respective layers L0 to L3. At this timing, the processingproceeds from the step F509 to the step F510.

In the step F510, the system controller 60 makes the optical pick-up 51access TDMA_N. In the step F511, the system controller 60 updates theOPC operation executable address (Next available Ln OPC Address) foreach of the respective layers L0 to L3. Specifically, because the OPCoperation of this time causes change of the address of the part to beused next in each layer, the latest TDDS in which a new “Next availableLn OPC Address” is described for each layer is recorded in TDMA_N.

As above, the OPC operation is completed. Thereafter, recordingoperation ordered by the write command is carried out with the optimumrecording laser power.

In the processing of FIG. 25, as one example for description, actualdata recording is performed after the TDDS recording processing in thesteps F510 and F511. However, the actual updating of the TDDS on thedisk 1 may be performed at a timing after the end of data recording orthe timing of disk ejection, power-off, or the like. This is to suppressunnecessary consumption of the TDMA area.

That is, the timing of the TDDS updating on the disk 1 does not need tobe the timing shown as the steps F510 and F511. Thus, this processing ofthe steps F510 and F511 may be regarded as processing in which thesystem controller 60 stores new TDDS information (in this case, “Nextavailable Ln OPC Address”) in the internal memory for at least TDDSrecording at a later timing.

The above-described OPC operation is one example. In this example, theamounts of consumption of OPC(L0), OPC(L1), OPC(L2), and OPC(L3) arealways equal to each other because the OPC operation is carried out forall the layers in response to the write command. Even though the amountsare not equal to each other in a precise sense because of the occurrenceof OPC retry or the like attributed to any error, the amounts can beregarded as being almost equal to each other.

Thus, “catching up” of the amount of consumption, by which the apparentgap distance disappears between two OPC areas in the pair, never occurs.

For example, a consideration will be made below about two OPC areas(OPC(L0) and OPC(L2)) in the pair described with FIG. 20. The address ofthe part to be used next (Next available Ln OPC Address) in OPC(L2),which is the chaser side in the consumption direction, and the addressof the part to be used next (Next available Ln OPC Address) in OPC(L0),which is the chased side, proceed toward the disk inner circumferencewith almost equal amounts of consumption. Therefore, it can be said thatthe possibility of the “catching up,” i.e. the possibility that theapparent gap distance AB1 becomes shorter than 150 μm as the allowabletolerance of the offset of the recording layers and disappears, issubstantially zero.

The execution of the OPC operation for all the layers in response toevery write command can be regarded also as unnecessary consumption ofthe OPC areas. Thus, e.g. the following processing way will also beavailable. Specifically, the OPC processing like that of FIG. 25 isexecuted only at the time of the first OPC operation after disk loading,and the OPC operation is not carried out at a later write commandtiming.

In this case, to address change over time, temperature change, and soforth, it will also be possible that the OPC processing for all thelayers is executed not in response to every write command but e.g. afterthe elapse of a predetermined time according to need.

Next, with FIG. 26, a description will be made below about a processingexample in which the OPC operation is carried out only for the layer inwhich recording will be performed in response to a write command.

Steps F401 to F408 in FIG. 26 are steps of the same processing at thetime of disk loading as that in FIG. 25, and therefore overlappingdescription thereof is omitted.

The following description will deal with processing of steps F601 toF612 as an example in which the OPC processing is executed in responseto issuing of the write command.

Upon the issuing of the write command, the system controller 60 forwardsthe processing from the step F601 to the step F602, where the systemcontroller 60 grasps the address ADD[n] at which the next OPC operationcan be carried out about the OPC areas in the respective layers. Thisaddress ADD[n] is indicated as the OPC operation executable address(Next available Ln OPC Address) in the above-described TDDS.

About each of the respective OPC areas (OPC(L0), OPC(L1), OPC(L2),OPC(L3)), the system controller 60 grasps the address ADD[n] from thelatest TDDS from which the address ADD[n], at which the next OPCoperation can be carried out, has been already read.

In the step F603, the system controller 60 discriminates the layer asthe subject of the data recording ordered by the write command of thistime.

The processing diverges to different courses depending on whether thesubject layer is layer L0 or L1 or it is layer L2 or L3.

Layer L0 or L1 is the layer in which the OPC area (OPC(L0), OPC(L1)) isthe chased side in the pair in the consumption direction.

Layer L2 or L3 is the layer in which the OPC area (OPC(L2), OPC(L3)) isthe chaser side in the pair in the consumption direction.

First, the case in which the subject layer of the recording is layer L0or L1 will be described below.

In this case, the system controller 60 forwards the processing to thestep F607, where the system controller 60 makes the optical pick-up 51access the address ADD[n] of the part to be used next in the OPC area inthe subject layer. For example, if layer L1 is the layer of therecording subject, the system controller 60 makes the optical pick-up 51access the address ADD[n] in OPC(L1).

In the step F608, the system controller 60 checks whether this addressADD[n] is surely unrecorded (i.e. whether the address ADD[n] can be usedfor the OPC operation). For example, the system controller 60 makes therelated units perform reproduction from the address ADD[n] to checkwhether the recording is present or absent at this address ADD[n]. Ifthe part from this address ADD[n] has been used, the system controller60 seeks an unused part and causes movement to this unused part.

In the step F609, the system controller 60 instructs the respectiverequisite units of the recording system to execute test write in thepart from the address ADD[n]. For example, the system controller 60makes these units carry out data recording operation by a predeterminedtest pattern, random data, or the like with stepwise variation in therecording laser power.

After the end of the test write, in the step F610, the system controller60 makes the part in which the test write has been executed bereproduced by the optical pick-up 51. At this time, the systemcontroller 60 measures the index values (e.g. the jitter, the asymmetry,the error rate, and the SAM value) corresponding to the respectivevalues of the recording laser power, and decides the optimum recordinglaser power.

In the step F611, the system controller 60 makes the optical pick-up 51access TDMA_N. In the step F612, the system controller 60 updates theOPC operation executable address (Next available Ln OPC Address) for thelayer in which the OPC operation has been carried out. Specifically,because the OPC operation of this time causes change of the address ofthe part to be used next in the OPC area in this layer, the latest TDDSin which a new “Next available Ln OPC Address” is described for eachlayer is recorded in TDMA_N.

The end of the step F612 is equivalent to the completion of the OPCoperation. Thereafter, recording operation ordered by the write commandis carried out with the optimum recording laser power.

Similarly to the processing of FIG. 25, the actual TDDS updating on thedisk 1 does not need to be performed at the timing of the steps F611 andF612. Thus, this processing of the steps F611 and F612 may be regardedas processing in which the system controller 60 stores new TDDSinformation (in this case, “Next available Ln OPC Address” in thesubject layer) in the internal memory for at least TDDS recording at alater timing.

As just described, the OPC processing is normally executed in accordancewith “Next available Ln OPC Address” if the layer of the recordingsubject is layer L0 or L1 and the OPC area as the chased side in thepair (OPC(L0) or OPC(L1)) is used in the OPC operation in this layer.

On the other hand, if the layer of the recording subject is layer L2 orL3 and the OPC area as the chaser side in the pair (OPC(L2) or OPC(L3))is used in the OPC operation in this layer, processing to prevent theoccurrence of “catching up” of the OPC area consumption is added.

This is processing of the steps F604 to F606.

If the layer of the recording subject is layer L2 or L3, the systemcontroller 60 forwards the processing from the step F603 to the stepF604.

In this step, the system controller 60 checks the apparent gap distancein the pair.

The following description will deal with the case in which the layer ofthe recording subject is layer L2.

At the timing of this step F604, the system controller 60 obtains theapparent gap distance AB1 in the pair shown in FIG. 19. Specifically,the system controller 60 obtains the address difference between theaddress ADD[n] in OPC(L2) and the address ADD[n] in OPC(L0) in the samepair, which are checked in the step F602, and converts the addressdifference into the gap distance along the radial direction.

It is appropriate in terms of obtaining of the gap distance AB1 afterthe OPC of this time that the address ADD[n] in OPC(L2) is not directlyused as it is but the address obtained by address forwarding from theaddress ADD[n] by the predetermined number of sectors used in the OPCoperation of this time is used.

The system controller 60 determines whether or not a predetermined gapdistance can be kept as the apparent gap distance AB1 in this pair.Specifically, the system controller 60 determines whether or not a gapdistance of at least 150 μm, which is equivalent to the allowabletolerance of the above-described layer overlapping error, is ensured.

If the gap distance AB1 equal to or longer than the allowable toleranceis ensured, the system controller 60 forwards the processing from thestep F605 to the step F607, and carries out the OPC operation of thistime from the address ADD[n] in OPC(L2) in layer L2 (F607 to F610).Subsequently, in TDMA_N, the system controller 60 performs TDDS writing(or storing for later TDDS writing) for updating the OPC operationexecutable address (Next available Ln OPC Address) about layer L2, inwhich the OPC operation of this time is carried out (F611, F612).

Thereafter, recording operation ordered by the predetermined writecommand for layer L2 is carried out with the optimum recording laserpower.

On the other hand, if it is determined in the step F605 that thepredetermined gap distance cannot be ensured as the apparent gapdistance AB1 in the pair, the system controller 60 forwards theprocessing to the step F606, where the system controller 60 executesprocessing of changing the OPC operation executable address (Nextavailable Ln OPC Address) about OPC(L0) in layer L0, which is thecounterpart of the pair.

This is processing of forwarding the part to be used next in OPC(L0) asthe chased side in the consumption direction because the sufficient gapdistance AB1 is lost when the OPC area as the chaser side (OPC(L2)) isused in the OPC operation of this time. In the case of OPC(L0), the OPCoperation executable address (Next available Ln OPC Address) isforwarded toward the inner circumference by a predetermined amount inthis processing.

The system controller 60 newly sets the OPC operation executable address(Next available Ln OPC Address) about OPC(L0) and stores it in theinternal memory, followed by processing forwarding to the step F607.

In the steps F607 to F610, the OPC operation for layer L2 as the subjectis carried out.

In the subsequent steps F611 and F612, the system controller 60 executesprocessing for updating of the OPC operation executable address (Nextavailable Ln OPC Address) about layer L2, in which the OPC operation iscarried out this time, and the OPC operation executable address (Nextavailable Ln OPC Address) changed about layer L0. That is, the systemcontroller 60 performs TDDS writing or storing for later TDDS writing.

Thereafter, recording operation ordered by the predetermined writecommand for layer L2 is carried out with the optimum recording laserpower.

In the above-described example, layer L2 is the layer of the recordingsubject. Also when layer L3 is the recording subject, the sameprocessing is executed in the relationship with layer L1.

As described above, in the example of FIG. 26, the OPC operation for thesubject layer is carried out in response to a write command, and at thistime the processing for keeping a gap distance of at least 150 μmequivalent to the allowable tolerance as the apparent gap distance inthe pair is executed.

Specifically, when the OPC area as the chaser side in the pair is used,the system controller 60 determines whether or not the necessary gapdistance (at least 150 μm) dependent on the allowable tolerance relatingto overlapping of the respective recording layers is ensured as theapparent gap distance. If the necessary gap distance cannot be ensured,the system controller 60 executes processing of changing the startposition of the part to be used next in the OPC area as the chased side.

This processing prevents overlapping of the parts to be used next in theOPC areas in the layer direction in the first OPC pair and the secondOPC pair even if the offset of the recording layers is the maximumwithin the allowable tolerance.

In the example of FIG. 26, the apparent gap distance is checked when theOPC area as the chaser side is used. Alternatively, in the OPCoperation, processing of checking the apparent gap distance may beexecuted irrespective of the OPC area to be used. Of course, also inthis case, one OPC operation executable address (Next available Ln OPCAddress) is changed according to need.

In the example of FIG. 26, the processing of changing the OPC operationexecutable address (Next available Ln OPC Address) is executed when theOPC area as the chaser side is used. Similarly, the processing ofchanging the OPC operation executable address (Next available Ln OPCAddress) may be executed when the OPC area as the chased side is used.

In the example of FIG. 26, the OPC operation executable address (Nextavailable Ln OPC Address) is acquired from the TDDS in the step F602.Alternatively, it will also be possible to seek the OPC operationexecutable address through search for the unrecorded part in the OPCarea. Therefore, in the step F606, processing for regarding theunrecorded part generated due to the processing of changing the OPCoperation executable address (Next available Ln OPC Address) as thealready-recorded area, or processing of setting the length of theunrecorded area shorter than the predetermined length may be added.

The disk of the embodiment of the present invention and the disk drivedevice capable of dealing with the disk have been described above.However, the present invention is not limited to these examples butvarious modification examples may be made without departing from thescope of the present invention.

DESCRIPTION OF REFERENCE NUMERALS

1: Disk, 51: Pick-up, 52: Spindle motor, 53: Sled mechanism, 54: Matrixcircuit, 55: Reader/writer circuit, 56: Modulation/demodulation circuit,57: ECC encoder/decoder, 58: Wobble circuit, 59: Address decoder, 60:System controller, 60 a: Cache memory, 61: Servo circuit, 62: Spindleservo circuit, 63: Laser driver, 120: AV system, 201: Disk substrate,203: Optically-transparent layer, 204: Intermediate layer

1. A recordable optical disk as a plural-layer disk comprising: at leastthree recording layers configured to be provided over a disk substrate;and an optically-transparent layer configured to be formed on alaser-incident surface side, wherein a test area for laser power controlis provided in an inner circumference side area closer to an innercircumference than a data zone in which user data is recorded in each ofthe recording layers, and the test areas in the recording layers are sodisposed as to be prevented from overlapping with each other in a layerdirection.
 2. The recordable optical disk according to claim 1, whereina management information recording/reproduction area for recording andreproduction of management information is provided in the innercircumference side area in each of the recording layers, and themanagement information recording/reproduction areas are so disposedthat, for each of the test areas in the recording layers, the number ofmanagement information recording/reproduction areas overlapping with thetest area in the layer direction at a position closer to alaser-incident surface than the test area is equal to or smaller thanone.
 3. The recordable optical disk according to claim 2, wherein themanagement information recording/reproduction areas are each so disposedas to be prevented from overlapping with the test areas in the recordinglayers in the layer direction on a disk substrate side of the testareas.
 4. A recording device for a recordable optical disk as aplural-layer disk that includes at least three recording layers providedover a disk substrate and an optically-transparent layer formed on alaser-incident surface side, the recording device comprising acontroller configured to dispose a test area for laser power controlabout a respective one of the recording layers in an inner circumferenceside area closer to an inner circumference than a data zone in whichuser data is recorded in the respective one of the recording layers ofthe recordable optical disk in such a way that the test areas areprevented from overlapping with each other in a layer direction, thecontroller carrying out control to perform information recording afterlaser power adjustment by use of the disposed test area.
 5. A recordingmethod for a recordable optical disk as a plural-layer disk thatincludes at least three recording layers provided over a disk substrateand an optically-transparent layer formed on a laser-incident surfaceside, the recording method comprising the step of disposing a test areafor laser power control about a respective one of the recording layersin an inner circumference side area closer to an inner circumferencethan a data zone in which user data is recorded in the respective one ofthe recording layers of the recordable optical disk in such a way thatthe test areas are prevented from overlapping with each other in a layerdirection, and performing information recording after laser poweradjustment by use of the disposed test area.
 6. A reproduction devicefor a recordable optical disk as a plural-layer disk that includes atleast three recording layers provided over a disk substrate and anoptically-transparent layer formed on a laser-incident surface side, atest area for laser power control being provided in an innercircumference side area closer to an inner circumference than a datazone in which user data is recorded in each of the recording layers, thetest areas in the recording layers being so disposed as to be preventedfrom overlapping with each other in a layer direction, the reproductiondevice comprising a controller configured to recognize a managementinformation recording/reproduction area that is so disposed in the innercircumference side area in each of the recording layers that, for eachof the test areas in the recording layers, the number of managementinformation recording/reproduction areas overlapping with the test areain the layer direction at a position closer to a laser-incident surfacethan the test area is equal to or smaller than one, and the managementinformation recording/reproduction area is prevented from overlappingwith the test areas in the recording layers in the layer direction on adisk substrate side of the test areas, the controller reproducingmanagement information from the management informationrecording/reproduction area and controlling reproduction of user databased on management information.